[Glock Glockler]

Check it out on this month's Shotgun news! It uses a 6mm PPC case and launches a 123gr pill at over 2600fps yeilding over 1800ft lbs at the muzzle and over 1000ft lbs at 500 yds and droping 41 inches at 500 yds with a 200 yd zero.

To be perfectly honest, I'd prefer using a 45mm Czech case for a bit more power, but the Glockler is pretty damn good as were likely to realistically see, and you'll soon be able to get an AR upper to shoot it in.

Cheers

[Chris Rhines]

Time to head over to the newsstand.

What is it, just a 6mmPPC case blown out to .264? What kind of magazine capacity are we looking at?

- Chris

[Glock Glockler]

Chris, it's the Sept. issue of SGN. The one with a lame FN shotgun on the cover. The October issue might already be out. Yes, it is a PPC case necked up to .264.

The AR that had chambered for it took a 5 rounder, but I think you could probably use any AK mag with success, or you might only have to modify it just slightly. The big determinant will probably be the 2004 sunset as to whether or not it takes off. Apparently it will be unveiled at the 2004 Shot show.

[El Tejon]

I'm a big fan of the 6.5mm family. Have to check it out.

Thanks for the head up, Glock.

[Glock Glockler]

http://www.competitionshooting.com/pages/708565/

A bit more info on the concept.

[atek3]

wait call me a fool but you are refering to the cover story regarding .26 grendel right, which is also based on 6.5 PPC.

atek3

[Futo Inu]

Right, atek; that's the one. He's foolin around with the name. I also like 6.5mm cartridges, BUT I think 6.0mm is better size for a medium-power military cartridge.

[Andrew Wyatt]

i wonder if it'll work in a mini.

[atek3]

hey futo, why do you say that?

For pure windbucking in a light cartridge 6.5mm can't be beat (unless I'm full of BS :) )

I think a 6mm would be an incremental inprovement over the 5.56, not worth the major costs of development.

atek3

[Badger Arms]

Hmmmm, 123gr at 2600 fps is not an improvement on the .223, it is just a somewhat less-powerful 7.62x51. Why not just neck down the 308 to 6.5mm... wait, that's already been done. Ah, heck, I just don't like the 6.5mm. The 7.62 and 6mm are good enough for me.

[Futo Inu]

I just think 6.5 is better suited to "standard, non-magnum" sized cartridges of .308ish size (i.e. the .260 Rem), but slightly smaller is better for a "medium" powered cartridge for an assault rifle capaple of being fired under control in full-auto, IMO, based on a calculus of all the factors - lemme link you to the discussion of the 6mm Badger - the goal is to get a 105 gr bullet to 3,000 fps, or purt close to it. Mr. Glock Glocker, and Mr. Badger Arms, who just posted, AYCS, are infinitely more knowledgable about this than me, and so maybe they can explain it better.

http://www.thehighroad.org/showthread.php?s=&threadid=40209&highlight=badger+AND+6mm

Badger Arms, et. al changed my mind about this - I was thinking 6.5 also, but well, just read that whole thread. Yes, the 6.5 bucks wind but the 6mm bucks wind almost as well and far better than any .224 bullet. The 105 grainer optimizes the BC in a 6.0mm bullet - up over .500 or so in that weight with a BT bullet - of course BC is not everything, but.....And 105 gr is a 169.35% heavier bullet than the 62 grain SS109, almost as fast in this theoretical round, and has a .500 BC versus .264 for the 62 grain .224.

[max popenker]

i wonder if it'll work in a mini.

As it is based on the ol'good 7.62x39 case, it surely will work in RPK and RPD with minimal alteration (new barrels).

RPK
http://world.guns.ru/machine/rpk.gif

RPD
http://world.guns.ru/machine/rpd2.jpg

I also really like to see one day the AK-103 (actually, AK-74M in 7.62x39) rebarreled to round like that, and with recoil buffer installed in the receiver. Then - screw the AK-74 and AN-94 :evil:

[Gabe]

Max,

Do you know why Soviet designers went to the 5.45 cartridge instead of simply necking down to a 6mm or some such caliber? That sure would've been a lot more cost-effective.

[max popenker]

the only thing i know for sure is that early experiments were made with necked-down 7.62mm cases, but i suppose that case diameter reduction was caused by the weight savings - note that complete 5.45mm cartridge weights 10 gramms, while 7.62x39mm cartridge - 16 gramms. This is saving of 1.2+ kg (~3lbs) saving per only 8 magazines (240 rounds). with the old case weight difference would be less.

i also must note that 6-6.5mm caliber was proposed in 1916 as an ideal automatic rifle chambering by the col. Fedorow, russian arms designer and historian.

[Grump]

I still vote for 6mm, closer to 90-105 grain bullet AND EXTEND THAT SHOULDER FORWARD. 2900 fps might be enough. If it shoots flatter than a .30-cal 155-gr Palma launched at 2800 fps, then that's fine.

The incremental gain is worth the effort if we get rid of both the 5.56mm and 7.62mm NATO rounds. No more SAW/MINIMI/M60 (or whatever replaced it)/M16 series/M14 ammo supply complications.

More powder....needs more powder. As long as the throat erosion doesn't get out of hand like with the .243 and more "overbore" cartridges.

[Glock Glockler]

Badger, you betrayed me:(

Although the ballistics on the 6.5 Glockler are not quite as those on the 6mm Badger, it is definately a few steps up from the .223. It has over 1000ft/lbs at 500 yrds and will have much better penetration than a .223 while being more compact than a .308.

[JShirley]

What he said. Ultimately, logistics are more important than almost everything else.

[Marko Kloos]

Wow...it duplicates the ballistics of the 7.62mm CETME.

[Gordon]

Just my $.02: I have used a 6.5TCU for my wife as a low recoil NON WOUNDING hunting rifle for 10 years or so. The 22" barrelled Sako reaches almost 2700fps with NoslerPartition 125grain bullets which blows a 1" hole thru the shoulders of deer sized game to 300yards. I do have a .264Win mag and a 6.5x55 with which I ocasionally shoot heavier bullets at greater velocity. I have a 25-06 with which I had trouble getting 120grain bullets to bust the shoulders of deer,great critter getter in the wind though. Ive seen enough 100grain 6mm 243'sand BRs to know what they can AND can't do. I love the .270Win and have 7x57, 7 rem mag and 7STW guns and it gets bigger from there. My point is I think around 120-125grain 6.5mm bullets travelling at least 2600fps give what is called "dual cavity hyper- excavatiom" on animals to 250pounds and exterpolation would indicate the same for humans. I think a controlled expansion bullet is the way to go , but if Geneva convention limits to FMJ then I think proper rifling pitch/bullet design can make it break up on human hits, ala 5.56mm. I think 6.5mm gives the desired flat trajectory because of high(enough)BC and has adaquate diameter for slap(momentum transfer) improvement over 5.56mm with minimum recoil. What I hope military research does is develop new powders for 6.5 TCU thereby allowing use of existing magazines with just a rebarrelling job with out a new bolt face ect. But since the free world rejected the almost perfect .276 Pederson, I guess engineers have to justify their research reinventing the wheel. I think 2600fps with 123grain bullet in 6.5TCU in an 18"barrel is obtainable NOW with latest availible powders.;)

[Badger Arms]

Glocker: Sorry, I'm just not that excited about 6.5mm guns. The difference between 6.5mm and the 6mm we refined earlier is large enough. The 6.5mm you're talking about in this thread has too little velocity for my tastes.... HOWEVER... I've got the issue you spoke of in my AK-47 bashing fingers right now, well, not right now as I'm typing, but you get the point.
Wow...it duplicates the ballistics of the 7.62mm CETME.You've got me LITERALLY laughing out loud. What a hoot. Cruel, but still funny. So what's wrong with the 7.62 CETME? Them poor Spaniards were too weak and needed a 7.62 NATO LITE! ROFLMBO

[Glock Glockler]

Badger,

What about 128grs @ 2750? According to the 2nd link I posted, that is attainable as well. The cool thing about the Glockler is that it's doable, while we'd have to go with a rather fat and short round or a .243 for the ballistics of the Badger. I'm also somewhat confused, as you mentioned in threads previous that you throught 2700fps would be the optimal muzzle velocity.

Also, I think the AK bashing thread is dynamite, I only wish you'd start designing your own guns.

[Badger Arms]

2700 is the minimum desireable terminal velocity. I'd rather have a higher initial velocity and a bullet that drops to 2700 at around 300 yards. What would make the 6.5mm improved enough from a terminal ballistics point of view to justify the increase in bullet weight and decrease in velocity... I still haven't read the article though, so I may be way off on this one. And for all of that matter, why not a 25 caliber? How about a 27 caliber? If we stick with common calibers, the 6mm makes up for most of the dificiencies of the .223 without the tremendous penalties we get as we increase diameter. A 6mm is roughly 20% larger than a .223. A 6.5mm is another 20% larger than the 6mm when speaking in frontal area and mass. That's rough, but it's a good way to visualize the factors at work here. So with a 6.5 we start out 20% larger than the 6mm, 20% heavier, and at at 3-400 fps slower.

On the plus side, we get lower pressures, an easier cartridge to make and chamber to an AR-15, and less recoil. Why not just use the 6mm ppc then if we're going this direction?

[Grump]

Why not just use the 6mm ppc then if we're going this direction?

Because the shoulder is about 5mm too far back.

a. Get a little more powder and deeper-seat the bullet.
b. This reduces the occasional accuracy- and reliability-robbing problem of rounds getting "bent" because the bullet is hanging way out there in the breeze.
c. It keeps the round from looking "funny" :neener: like those original 6.5x55 and .30-03 rounds.

I kinda doubt that the little bit extra powder would increase throat erosion much over the regular old 6mm PPC.

Who's gonna cook us up some "6mm PPC Grumpy Improved" rounds off of a Chech 7.62x45 case? Okay, we can still call it the 6mm Glockler.:)

[Futo Inu]

Take with grain of salt, as I am not nearly the expert as some of you, but a few thoughts come to mind here:

1. Look at the cases of the 6mmPPC and the 6mm Remington Benchrest. The 6mm Remington benchrest is a little fatter, and thus nicely splits the difference between the PPC and using the .284 cases for the new round. The 6mm Rem BR with shoulder forward would be nice starting point seems to me, for a case to use, especially in light of the points I will make below. This case is based on a .308 case with a small primer pocket.

2. Someone said (Gordon? hang on, I'll look back...) that one of the factors to consider is not being so overbore as to have the "out of control throat erosion" of the .243. Assuming this is the important factor that it appears to be, then - It occurs to me that there is NO WAY to not have this happens (being over bore), IF you have ballistics of the .243 (i.e the goal of the 6mm Badger), UNLESS somehow short fat cartridges erode less than longer, skinner ones (I doubt it however). After all, max loadings in .243 with 105 ONLY get you vels of 2800-2950 or so, from a 24" bbl, no less. So, the question becomes, what factors exactly is throat erosion a function of, and how exactly would the "6mm Badger" be different in terms of those factors? This leads me to think that the goal should either be 105@2700-2800 (from a 20" bbl), instead of 2900-3000, in which case we're back to maybe a slightly smaller case than Badger had in mind (such as the 6mm Rem BR), OR - *OR*, use a larger bullet (a la Glockler). How, having said that, perhaps it's the case that you only get excessive erosion from lighter bullets going 3200+ give or take - I just dunno, but if so, then this is NOT a problem, as we all seem to agree on using long, heavy, good BC bullets, regardless of bullet size.

3. Next, IF the debate ends up becoming "6mm or 6.5mm" (as it possibly seems to be, in part), then like a load of bricks, the obvious answer becomes - SPLIT THE DIFFERENCE - use a .25 cal bullet! Maybe the goal should be .257 bullet - 100@2,900-3,000 or 115-120@2,700-2,800, maybe a little less in a 6mm-Badger-ish case? My vote would be the 100-105 6mm at 2,700-2,800, not stepping up to the .257, in part because I think it's harder to duplicate say .250-300 savage ballistics in a shorter round than it would be to duplicate almost-.243 from a shorter round in .6mm.

But it seems to me that the key is, still with 6mm but not quite attaining the (possibly unnecessary) velocity goal of the "6mm Badger". Number one I think it's flat unrealistic to obtain from any case under 1.8", even the .284. Number two, you can have have more mag capacity (using a PPC or 6mm Rem BR -ish). Number three, you have slightly more controllability in full-auto. Number 4, you can have more taper, and thus better extraction. Number 5, the important factor of this overbore issue - how can you deal with that, Badger Arms? I like the 100-105 6mm @2,700-2,800; maybe 2,600 from a shorty/carbine, and 2,500 in a M4ish/CQB version. But a .257-based round being the second choice, and the 6.5 Glockler being the third choice. BTW, is there such a thing as a .23 caliber bullet? Halfway between .224 and .6mm? That would further complicate the debate (thus making it more fun. :) )

[BTW, of course all of these rounds solve the logistics problem, because one of the key precepts, for better or worse, is to use but one round in all small arms - assault rifle, battle rifle, CQB, SAW - the question is, WHICH round to settle on.]

If my idea (6mm Badger lite) ends up being the 6mm FUTO, then so be it, but someone else should jump on it, because it's just as "doable" as the 6.5 "Glockler" and it gives higher vels, giving you the possibility of some wicked bullet activity in the terminal ballistics, like a 5.56 round, esp. if you take it down a notch in bullet size to say, 87 grains. In fact, the 6mm FUTO would be ideal for both handloaders and military alike because the military, for logistics reason, could use say, a 90-95 grainer to split the difference, for all small arms purposes, and handloaders/police/general public would use 105 grainers for 20-24" bbls, 87 grainers for 16-18" bbls, and lighter for lighter (58-80) for CQB, 10-14" bbls, to get identical velocity (and therefore terminal ballistics) results. Or, anyone could use 60 grain screamers in any bbl length for varmints or whatever. I keep coming back to the "6mm Badger lite" - a .308 based case like the 6mm Rem BR. Can anyone tell me, is there a "magic" velocity number at which an average FMJ spitzer bullet will yaw and tumble in terminal ballistics like a .223? Is it 2600? 2650? 2750? 2800? 2850? 2900? Or more? If there is, then that should be the goal - just download the bullet size from 105 to get there in any given small arm, and use the least common denominator for military logistics reasons (whatever weight gives you the magic vel number in a 14" M4) - be that 87 grains or whatever, and take your hickey on penetration/BC (yet still better than the .224), but stick with 6mm (or possibly .257), because it's so much easier to obtain the desired vels from a 6mm vs. a 6.5. Simple question - does the 6.5 glockler/grendel tumble when it hits flesh? If not, then we're not there yet, are we, given Geneva convention restraints? If 2800 still doesn't cut the mustard, then run with the 6mm Badger or the Badger lite with 87 or lighter bullets, pumping out at 3000, but I'd imagine that from a M4 length bbl, to get 3,000, you'd have to dumb down to a 70 grainer from a Badger lite. The key is, what is the magic number for getting a tumbler? :)

4. Finally, Badger Arms, you said that a 6mm is about 20% larger than a .22, and a 6.5 is about 20% larger than a 6mm. Well, sorta, kinda, maybe, not really. :)

Precisely, a 105 grain, 6mm bullet is 69.35% HEAVIER than a 62 grain .224 bullet, but only 8.48% wider frontal area/diameter (if you want to call that 20%, then OK - perhaps you're referring to energy, but this depends very much on which exact load you're talking about, since the velocity is squared in an energy calculation). I would suspect that the PENETRATIVE ability of a bullet is not any kind of average of those two, but rather a factor of the two, which should roughly approximate the BC of the bullet (since the BC is a measure of how the bullet cuts through wind, and penetrating/cutting through the terminal material is a similar prospect, as a general matter of physics - only difference being bullet construction/material becomes an ADDITIONAL factor over and above the BC-related factors when you reach the terminal material - BUT whatever bullet is used is going to be of similar construction regardless of diameter and weight) - and a 105 grain 6mm has a BC of .500, which is an 88.67% improvement in BC over the 62 grain .224 (.265 BC). Actually, isn't the penetrative ability going to be essentially the BC, with a certain added "bonus" to the overall weight of the bullet? (ASSUMING identical construction/materials of the bullet - i.e. FMJ spitzer, regardless of bullet size). Therefore, I would think that a bullet which has a 88% better BC AND 69% more weight is going to penetrate better somewhere on the scale of 90% to 100% better, but we need a physics expert....

A 140 grain 6.5 mm bullet is 25% heavier than a 105 grain, 6mm bullet, and 125% heavier than a 62 grain, .224 bullet. A 6.5 mm bullet is 8.6% larger diameter than a 6mm and is 17.85% larger than a .224 bullet. A 140 grain 6.5mm bullet has approx. (only) 4% better BC than a 105 grain 6mm bullet, but has a 96.23% better BC than a 62 gr, .224 bullet! This bullet is going to be the king of penetration in any reasonable sized round.

Bottom line however, without the need for a physics expert, it is readily apparent that the 6mm is light years beyond the .223 in BC and penetration, whereas the 6.5 is only a smidge better than 6mm in BC and penetration, in a nutshell.

Gordon, you said, "Ive seen enough 100grain 6mm 243'sand BRs to know what they can AND can't do." Please expand on that - what can't they do, in a 250 lb or smaller target?

Again, worth 8 cents (4 points @ .02 each :) - more or less).

[Glock Glockler]

Futo, very thorough, thanks for your contribution.

Also, thanks to you as well, Gordon. I did know that the veolcities would rise along with increasede barrel length but I didn't quite expect the velocities you've gotten. I am partial to the Russian case, as it's shorter and has more power capacity.

Badger,

We still have the problem of taking the Badger from theoretical to the actual. Even with a .308 case we're still not quite at the ballistics you want, so we'd then have to go to a short fatboy to achieve it, so we're going to be severely limiting magazing capacity. Granted, I love the ballistics but like the Old Mainer says "Yeh cahnt get thehr from hereh". If we stuck with 6.5mm rounds and went up to a 45mm case we'd be able to pull off even more, getting pretty damn good ballistics in a reasonably sized case.

[Badger Arms]

Futo:

Frontal area calculations were based on the formula Pi times R squared. That means you divide the diameter by 2, square that, and multiply by 3.14. So that gives us the following presuming a .250 sectional density:

.224" -- 88gr --- .039" Frontal Area
.243" -- 103gr -- .046" Frontal Area -- 17.7% Increase
.264" -- 122gr -- .055" Frontal Area -- 18.0% Increase

Just for kicks, here's some other numbers:

.277" -- 134gr -- .060" Frontal Area
.284" -- 141gr -- .063" Frontal Area
.308" -- 166gr -- .075" Frontal Area
.323" -- 183gr -- .082" Frontal Area
.338" -- 200gr -- .090" Frontal Area
.358" -- 224gr -- .101" Frontal Area
.375" -- 246gr -- .110" Frontal Area

Playing with the numbers is very interesting. For some reason, standard market bullet weights get smaller as you get below 30 caliber. At any rate, I was only 2.3% off on my guestimate calculations. The 6mm bullet is 17.7% greater in frontal area than a 5.56mm bore and the 6.5mm is 18% greater in frontal area than the 6mm.

We still have the problem of taking the Badger from theoretical to the actual. Even with a .308 case we're still not quite at the ballistics you want, so we'd then have to go to a short fatboy to achieve it, so we're going to be severely limiting magazing capacity. Granted, I love the ballistics but like the Old Mainer says "Yeh cahnt get thehr from hereh". If we stuck with 6.5mm rounds and went up to a 45mm case we'd be able to pull off even more, getting pretty damn good ballistics in a reasonably sized case.After reading the post and doing some reflecting, I'm convinced that utilizing an AR-15 action and conventional (220 Russian diameter) base for a conventional bolt requires that we use a smaller case capacity. How about turning the 284 base down from .473" to .440" like the 6mm PPC. We'd have a super-rebated rim, yes, with all of the resulting reliability issues. Nah, that doesn't sound doable. Is it possible that the 6.5mm Grendel necked down is as much as we're going to get? I'd still like to see 3,000fps so that leaves us with a lighter bullet. Man, I'm thinking 87 grains. History repeating itself? Duplicate the 250/3000 in a .243 caliber gun with a shorter action?

It does, however, occur to me that the shoulder is way too far back. Why not let the bullet telescope into the case for more capacity? In other words, push the shoulder forward about 5mm or so. That would also allow more reliable feeding if you ask me. I'm also not sure how much taper is built into this case... As you know, I like more taper.

[Gabe]

If you intend your new cartridge to have military application, becareful not to squeeze every last ft/s out of the case. Remember it'll be fired from red hot cyclic actions so mind your pressure peaks.

[Badger Arms]

Okay, here's my rendition of the 6.5mm Glocker. It's in the center. From left these cartridges are the SS109, 6.5mm Grendel, 6.5mm Glocker, 7.62x39, and 5.45x39.

http://www.thehighroad.org/attachment.php?s=&postid=520956

[WonderNine]

I just don't understand this stuff. You go with a 6mm 100gr. whatever and it's not going to fragment and create massive wounds (FMJ that is) unless you put a massive powder charge behind it to push it to at least 3200 fps at the muzzle for a good 100 yard zone of destruction.

You want armor piercing??? You just can't have that unless you go with a powerful, heavy to carry round (compared to the .223) and shoot it out of a long barrel. It's just basic physics here folks.

But then you're back to the same old problem of heavier ammo, so why not just stick with the .308?

Oh boy, here come the flames....

[Badger Arms]

Not going to flame you, but you don't have to push the 6mm bullet out to anywhere near 3200 fps. A muzzle velocity of 2700fps produces satisfactory fragmentation in an American FMJ round. If you push a VLD bullet at 3000fps, you will be above that 2700fps point over a greater distance. Besides, the 2700fps is not a magic number. If you use Russian technology and design your bullet like their AK-74 round, you'd probably greatly increase the effectiveness.

As for armor piercing, the SS109 penetrates better than the 7.62 Nato. Go figure. Why not stick with the .308? Because we KNOW that the 7.62 NATO is impossible to control in a sub-10 pound rifle on full-auto.

[Grump]

Why not stick with the .308? Because we KNOW that the 7.62 NATO is impossible to control in a sub-10 pound rifle on full-auto.

And...

We want more rounds per magazine-stack.

We want to have ammo lighter than 7.62 NATO.

We want to reduce shooter fatigue, which = increased hit probability at the end of the battle.

We want to use less copper & powder & lead per round than 7.62 NATO.

We want to have increased range, increased soft-target penetration, and increased light-armor target penetration than the 7.62 NATO. The penetrator-tip approach for Ball ammo is, I believe, well-proven and decreases the need for more spendy AP rounds, without *necessarily* losing the bullet yaw/fragmentation benefits in soft targets at closer range. My sources indicate that many combat units in WWII were routinely issued nothing but AP.

AND

We want to get the small arms ammo back down to 2 rounds, rifle and pistol/maybe smg.

[Futo Inu]

Badger:

"History repeating itself? Duplicate the 250/3000 in a .243 caliber gun with a shorter action"

How is duplicating 250/300 in 6mm with a shorter action, history repeating itself? True, there is ordinarily nothing new under the sun, but what specifically are you referring to? Can you comment on using the 6mm Rem BR with a slightly-forward shoulder, as a base case for your round.

Duplicating the 250/3000 with 6mm in a shorter round sounds good to me - that's what you want. 87-90 grains of 6mm doing 2,900-3,000 out of a 20" bbl. It's still doing 2700+ in a CQB rifle, enough to fragment and/or tumble. Perhaps the goal should be "still doing 2700 at 100 yards from a 14" bbl, and still doing 2700 at 300 yards from a 20" bbl" - you'd have to do some algebra and backtrack from the BCs etc. For a 300-500 yard hit, you just can't expect anything more than a hole-maker, IMO, so this is a workable idea, no?

[Gabe]

Badger Arms:
As for armor piercing, the SS109 penetrates better than the 7.62 Nato.



Hard to believe. Source?

[Grump]

Gabe, it's been hashed to death elsewhere, but it applies to the helmet penetration tests NATO uses. For ARMOR plate, I believe that M855 still does worse than Mwhatever 7.62 NATO AP, while it may or may not beat M80 ball, depending on the distance to target and the thickness of the light armor.

Sandbags and enemy troops are another matter altogether re: penetration.

[Badger Arms]

How is duplicating 250/300 in 6mm with a shorter action, history repeating itself?Well, I am trying to get a 6mm bullet to fit into a certain action and go a certain velocity. The only option we're left with is to adjust the bullet size until we reach the proper velocity. Savage chose 87gr for their bullet weight not because it was standard, but because they could reach 3,000fps with that bullet in their case, their gun, their barrel length, and their pressure limitations. The process is the same one Savage went through designing their round. That's what I meant, I didn't mean to say I didn't like the idea or that it had been done before, only that this isn't that difficult a task.

Gabe: Like Grump said, the facts are there. The steel nose of the SS109 is essentially an armor-piercing design. It's designed as essentially a compromise between FMJ ammo and Armor piercing. The 7.62 AP round is another story and will probably outdo the SS109... but be careful how you frame your mindset on penetration. Don't make the mistake of thinking that more power means more penetration. What your are looking for is sectional density and velocity. Two given bullets of exactly the same design, same sectional density, and same velocity should yield approximately the same penetration. The 7.62 AP round has a bit of an edge in the SD area, but it lacks the velocity of the SS109 round.

Source? Well, of course I have a source:

http://www.thehighroad.org/attachment.php?s=&postid=522721

[TX65]

Hi,

A friend of mine told me about "thehighroad.org" and the discussion on the 6.5 Grendel. If you have been to http://www.competitionshooting.com, I am the owner, author and experimenter who started this whole thing 5 years ago.

While not an employee of Alexander Arms, I have been happy to share my development and data with them in the creation of a production 6.5 Grendel.

Feel free to post or email with any questions you have and I will be happy to answer. Since I am a late arrival, I will answer some of the questions that have been put forward.

Magazine Capacity?

10 rounders for civilians, 25 rounders for the military and law enforcement.

Velocity quoted in Shotgun News vs velocity at competitionshooting.com?

I have acheived 200 fps more then the loads in the Shotgun News article. I am running with 2 inch longer barrel and moly bullets. Alexander Arms is keeping pressure below 45,000 PSI since they will be producing factory ammo.

Why 6.5 mm and not 6mm?

A 105 grain 6mm bullet is longer then a 128 grain 6.5mm bullet. Seating a 105 grain 6mm in an AR15 magazine requires pushing the bullet back in the case for a magazine length load. The 128 grain bullet is a perfect fit for magazine length loads.

While AR15 match rifles have been built in 6 PPC, a compromise is made for magazine length ammo with the 105 grain unless you cut the front out of the magazine to let you seat to 2.330".

The 6.5mm bullets in the 120-130 grain range are superior to the 105 grain 6mm bullet due to equal or slightly better ballistic coeffidents and increased bullet weight. For hunting or the military, this has value and the slight increase in bullet weight does not come with a recoil penalty.

Will it work in an AK or Mini 14?

You are more then welcome to experiment for your spirutal edification. However, be aware that the AK magazine is designed for the very tapered case of the 7.62x39 (that magazine curve has a purpose). Question would be why when you can have an AR that has been tested and refined without all the frustration.

Comment - the production version of the 6.5mm Grendel will be an improved version of the 6.5 PPC with slightly more powder capacity due to a shorter neck and shoulder pushed forward thanks to the engineers at Lapua. As noted in the article, the rifle in the article has a long throat and 1/9 twist. My original rifle has a 1/8 twist and a shorter throat which will become a part of the production version.

PS - I now have a 6.5 BR AR15 with the case rim rebated down to a PPC head diameter. The experimenting continues....off to the range next Tuesday.

[Badger Arms]

TX65:

Welcome to the board. My first question, I can probably answer myself. If you look at my doctored up photo above, you'll note that my case is longer with a shorter neck. The reason you didn't make the case longer is PROBABLY because the Parent Cartridge was too short. Why such a long neck, though? If you were to telescope the bullet back into the case and have a longer case, wouldn't you end-up with greater case capacity? I'm speaking from reloading experience with the OTHER short, fat 6.5, the 6.5mm Remington Magnum and it's more successful sibling, the 350RM.

The 6mm VLD bullet MIGHT be longer than the 6.5, but with nearly identical Sectional Density in these weight ranges, I'm skeptical. I haven't seen the bullets though. Assuming it's longer, I'm still wondering how that makes that much of a difference. There is no rule that says you have to have the shoulder where the base of the bullet is. The bullet can, in theory, telescope fairly close to the flash hole! I like the new cartridge, don't get me wrong, just push the shoulder forward and pump out a few hundred more FPS and you'd be fine and could even approach the low pressure levels that the maker wants.

Will the rounds fit in a modified AR-15 .223 magazine? If so, how many will fit in there?

I disagree that the 6.5mm in that range is superior. In fact, it's about equal. The 6.5mm at an SD of .250 yields 122gr and the same SD in the 6mm yields 103mm. Sounds like your SD is about the same as a 105gr 6mm bullet.

Heavier bullet means greater recoil.

For kicks, do you know if a .473" base can be accomodated in a standard AR-15 upper... even if the barrel extension has to be replaced in addition to the bolt, extractor, ejector, etc? Any ideas?

Also, what is the taper on the case? Is it less taper than the .223?

Final observations. From a semi-automatic point of view, I don't see any problem with your creation. I think that there will be a limited usefulness for Military and Law enforcement market and that should yield some results.

[TX65]

Badger,

Thanks for your questions,,,


Q1

""My first question, I can probably answer myself. If you look at my doctored up photo above, you'll note that my case is longer with a shorter neck. The reason you didn't make the case longer is PROBABLY because the Parent Cartridge was too short. Why such a long neck, though? If you were to telescope the bullet back into the case and have a longer case, wouldn't you end-up with greater case capacity? I'm speaking from reloading experience with the OTHER short, fat 6.5, the 6.5mm Remington Magnum and it's more successful sibling, the 350RM."""

A1

The initial cartridge was based on the PPC due to availablility of brass. The rifle pictured on my site was built not just as an experiment, but as a match rifle so I had to consider availability of quality brass. I didnt pursue a shorter neck with the shoulder pushed forward for simplicity in intial development. However, as stated in the article, in the production version of the 6.5 Grendel, the shoulder is pushed a forward and the neck is shorter based on improvements suggested by Lapua's engineers for production efficency.

Q2

The 6mm VLD bullet MIGHT be longer than the 6.5, but with nearly identical Sectional Density in these weight ranges, I'm skeptical. I haven't seen the bullets though. Assuming it's longer, I'm still wondering how that makes that much of a difference. There is no rule that says you have to have the shoulder where the base of the bullet is. The bullet can, in theory, telescope fairly close to the flash hole! I like the new cartridge, don't get me wrong, just push the shoulder forward and pump out a few hundred more FPS and you'd be fine and could even approach the low pressure levels that the maker wants.

A2 - There is a limit on how you far can push a bullet back in the case since you cant use the ogive of the bullet as a support in the neck. A case as you depict would severely restrict the range of bullets that can be fired from a magazine length load. For example, a bullet with a .750" ogive would be limited to a 1.505 case length to maintain 2.255 OAL. Even when seating the bullet back in the case, the capacity gains are offset by the volume of the bearing surface consuming case capacity.

As answered in A1 and stated in the article, the shoulder is pushed a tad bit forward with a shorter neck in the production version of the 6.5 Grendel.

Q3

Will the rounds fit in a modified AR-15 .223 magazine? If so, how many will fit in there?

A 3

Yes, in production magazines for the AR15, there will be 10 round capacity for the civilian market (in compliance with current laws) and 25 round capacity for the military and law enforcement.



Q4

I disagree that the 6.5mm in that range is superior. In fact, it's about equal. The 6.5mm at an SD of .250 yields 122gr and the same SD in the 6mm yields 103mm. Sounds like your SD is about the same as a 105gr 6mm bullet.
Heavier bullet means greater recoil.

A4

For comparison, a 123 grain 6.5 Lapua Scenar has an improved BC over the 105 grain 6 Lapua Scenar, but with 18 grains more bullet weight. At equal velocities, the 123 will deliver greater energy and a greater wound channel.

Recoil of the 6.5 is very mild in the rifle.

For many years, there has been research as far as what caliber would be the ideal military rifle cartridge. It is is well known that the ideal caliber would be between 6mm and 7mm. Of course, opinions abound with 5 current calibers in that range.

Q5

For kicks, do you know if a .473" base can be accomodated in a standard AR-15 upper... even if the barrel extension has to be replaced in addition to the bolt, extractor, ejector, etc? Any ideas?

Also, what is the taper on the case? Is it less taper than the .223?


A5

Ther are people who have machined open the AR15 bolt to handle the .473" base. However, that is with risks that can lead to a catastrophic bolt failure. There are experiments out there to make a bolt that can accomodate the .473" base, but they are not complete or proven at this point in time.

The case taper is standard PPC, not more, not less.

Q6

Final observations. From a semi-automatic point of view, I don't see any problem with your creation. I think that there will be a limited usefulness for Military and Law enforcement market and that should yield some results.

A6

In semi-auto operation, the round works great, is highly accurate with mild recoil functioning in an AR15 from the magazine. For target shooting, the round, using selected bullets, retains supersonic flight and sub MOA accuracy to 1,000+ yards. For hunting, the round delivers effective terminal energy and humane kills on a wide variety of animals in the 200-300 lb range such as deer and boar.

I cannot confirm or deny nor would I be at liberty to discuss applications of the 6.5 Grendel being considered by the US Dept of Defense.

[Glock Glockler]

TX65,

I tip my hat to you. Great job for working on this concept before I was even into guns, I guess great minds do think alike:)

What velocities would be possible using a barrel as short as 18 inches? Ideally I'd love to see something like this round developed into a bullpup rifle, so that we could still utilize a long barrel, but the practical reality favors the M4 type setup with a neutered barrel.

[Badger Arms]

Wow, straight answers. Thank you very much. I'm sold on the cartridge.

My only changes would be an increase in diameter for the parent case, however the comment I've read that the PPC case is as large as you can make it for a double-column magazine on the AR-15 makes perfect sense.

Practically, this round could have been made an 6mm, 25 caliber, 6.5mm, 270, or even 7mm. Twer it me, I'd have low-balled it for the velocity.

[TX65]

Glocker,

Alexander Arms is prototyping 16 and 24 inch barrel versions of the 6.5 Grendel. I believe the 16 inch barrel version will be at the Gunstock event in Waco, Texas on Oct 10,11 and 12.

The 123 Lapua Scenar in the 24 inch barrel is running 2616 fps with single digit velocity spreads. I am going from memory here so dont hold me to it, but I remember that in the 16 inch barrel it was running 2450 fps so a 176 fps drop over 8 inches. Doing some fuzzy math, that would 22 fps per inch change in velocity so an 18 inch barrel would be right at 2500 fps. Given that I use a 26 inch barrel, the 2616 number for a 24 inch barrel is about right with what I was achieving with the same powder and charge.

Keep in mind that velocity numbers are for prototype production ammo. The actual production ammo will have slightly more powder capacity then the prototypes. Given that extra capacity, I would say the 123 Scenar will be right around 2500 fps in a 16 inch and on + side of 2650 fps in a 24 inch.

If you want to contemplate the potential of this round, I will put this thought in people's mind.

According to the Lapua loading manual, A .308 Winchester with a 185 grain FMJBT is equal in ballistic coefficent to a 6.5mm 123 grain Scenar (better to compare same brand bullets for fairness) In the .308 Winchester, the maximum load is 2550 fps. In the 6.5 Grendel, you will be looking at a production (not maximum) load of 2650 fps.

Yes, the 185 FMJBT will deliver more down range energy due to its greater mass, but at a cost of more recoil, greater ammunition weight and needing a bolt action or AR10 to do it.

Badger,

Dr. Lou Palmisano and Ferris Pindell (the creators of the PPC family) originally made the PPC in 5.56mm, 6mm, 6.5mm, 7mm, and 7.62mm. Because both men are benchrest competitors, the 5.56mm and 6mm came into prominance and dominate benchrest competition, but Dr. Palmisano in one of my last conversations with him said that he uses a 7.62 PPC for deer hunting.

[uglygun]

TX65, nice to see you here....

In another thread where this concept was first being discussed I mentioned the 6.5mm PPC and linked to your page where you discuss the 6.5mm PPC advantages in current designs chambered for 5.56Nato, it's great to find you here to answer questions.

Would have come running to grab you from AR15.com sooner if it wasn't for the stupid forums being down.


It's interesting to discuss the difference between the 6.5mm PPC and the newer 77grain loads for the 5.56x45mm that are in an effort to put performance back into the M4. The 77grain rounds even at lower velocity are still showing quite a lot of wounding/fragmenting potential even though they are being fired at much lower velocities from the M4 length barrels. If the 77grain round can work at lower velocities, there shouldn't be too much trouble to make a 6.5mm bullet with weights ranging from 85-120grains in weight perform as well even if they are below 3k fps muzzle velocity.

A 100+ grain bullet at 2600fps would likely do quite a job down range. Can't help but wonder what a selection of 6.5mm PPC offerings would allow for, say a general use 85grain bullet that has a design similar to that of the SS109 bullet that carries a lot of velocity at closer ranges combined with increased frontal area and energy upon impact. Then a load with a heavier VLD bullet could also be in the inventory for even longer range encounters.

[TX65]

Glad you found me here....

In 6.5mm there are many options of projectiles for different applications. In the 100 grain and below weight range there are Speer - 90 grain TNT; Hornady- 95 grain VMAX and 100 grain SP, Sierra - 85 and 100 grain HP, Nosler- 100 grain Ballistic Tip and Partition and Lapua - 100 grain FMJ.

In my development, the lightest bullets I have measured across a chronograph has been the 107-108 grain HPBT bullets. In those tests, velocity has been running about 200 fps faster then the 120-130 grain bullets.

Stepping down in weight to these flatbase or minimal BT bullets and you have 3,000+fps performance. Even with a short barrel, these little rounds would be zipping along. For ranges out to the 300 yards would be very potent.

[atek3]

The .26 grendel/ AR combo seems almost perfect...but what about the direct gas impingement of the AR system... Fine on the range, but under real world conditions the added reliablity of a gas pistol/ regulator would really help the design. Are other gun companies going to be allowed to chamber their AR's in .26 grendel or will this make it a 'proprietary cartridge'?

atek3

[uglygun]

I'm thinking it will be semi-proprietary.

Once it gets out onto the market, it won't belong until folks are fire forming their own cases so they can handload for the round rather than buy the things outright.


Look at SSK Industries and their 300Whisper, the name is a proprietary critter but there are plenty of other folks out there doing 300/221 offerings. The important thing is how the rifles are tuned though, I guess SSK industries really knows how to work the uppers for the best reliability with the 300Whisper. Other's haven't quite yet backwards engineered what SSK Industries does, not sure if it's gas port diameter or length that makes it so "right".


If the Grendel succeeds then competition will probably follow to fight for a share of the market.

I've been dying for a 6.5PPC type offering for some time now but it's likely I'll just do a 260Rem for my AR10 instead as I'm looking for an accurized long range stick, would rather have the capacity of the 308Win family cases pushing a 123grn 6.5mm Scenar than that of a 220Russian family case.

[TX65]

The 6.5 Grendel in some ways will be proprietary, in so far as the magazines and the brass. When taking a wildcat to production, you can either hope someone like Winchester or Remington chooses to adopt it for one of their rifle offerings or you form a relationship with a brass manufacturer such as Lapua to produce the brass under contract (ie,,250,000 pieces of brass at a time).

When creating any non-.223 Remington cartridge for the AR15 like the "Grendel" you also have to consider the issue of magazines. To make the Grendel a valid production offering, Alexander Arms had to make an investment in time and resources to be able to provide standardized production magazines for the Grendel rather individually hand tuning magazines to work. Uppers and Rifles produced by them will be accurate, reliable machines offered at a reasonable cost. The majority of the people will use an Alexander upper as is or add accessories to serving their unique purposes. However, there will be a market for specialized versions for serious competitors in practical and highpower disciplines. As such, specialty gunsmiths like Scott Medesha, Derrick Martin and a few others may choose to include the Grendel in their offerings using magazines and brass from Alexander Arms. At this point in time, other then "bolt on" accessories and specific modifications like side charging handles, the only real specialty items I see gained in a specialized version will be use of a barrel brand other then a Lother Walther.

As far as Armalite, Colt, Bushmaster or DPMS offering a 6.5 Grendel under a different branding, I would say that is unlikely since they tend to only produce rifles in calibers that have mass produced factory ammunition. There will be other smaller manufacturers who offer a similar round such as a basic 6.5 PPC with standard shoulder location and neck (SSK Industries recently started listing a 6.5 PPC as one of their offerings) but you will be forced to form your own brass from Lapua .220 Russian, Norma 22 PPC or 7.62 x39.

As far as designing a new gas system,,,I dont see that being a priority for anyone. The AR15 platform as a military rifle will begin being phased out by the end of this decade. By that point in time, the platform will be over 50 years old and the military is already headed in a new direction with the H&K machine that fires programable air burst ammunition as well as conventional rifle ammunition. I think the only thing that will prolong total phase out of the AR15 platform will be budgetary considerations of the government. Of course, the average person will never be able to own the new rifle system.

[Glock Glockler]

TX65,

Have you ever done any type of penetration tests with 6.5mm on Kevlar or on media such as steel plates, sandbags, packed snow, etc?

Badger,

Wouldn't the OAL be longer on the 6.5mm Glockler (6.5mm x 45mm Czech) than a standard 6.5mm Grendel? On the picture above they seem to have the same OAL.

[TX65]

Personally, I have not done any penetration tests with the 6.5 Grendel. My testing has all been related to accuracy, velocity, bullet drop and windage.

I use 2.255" max OAL for all rounds since magazine length performance is my goal and the throat is cut for that. The only rounds which fall below the 2.255" maximum are those using 100 grain or less projecticles.

If the 6.5 Glocker has a 45mm case length,,, I would think OAL would be similar to the 6.5 TCU. In the past I contemplated the idea of finding a longer version of the PPC. Unfortunately, my development projects are working experiments and using an odd case would not be practical. Another issue that sidelined this was match bullet dimensions. If a bullet has an ogive length of .750", then the maximum case length that would still fit within an OAL of 2.255 is 1.505". Going to a 1.605" case would limit the maximum ogive length to .650" which limit bullets selection.

[Badger Arms]

What about using the 35 Remington as a parent case with the rim turned down? Extra length, more steps to make though and SLIGHTLY more case capacity.

[JShirley]

TX65,

Nice of you to come by and answer some questions. Have you fired the new 6.8x43mm for comparison?

Specs a little over 2700 fps for 110 grn bullet from 18" bl.

John

[TX65]

From time to time, people ask me about the 6.8x43 and you are first on this board so let me lay out my thoughts and impressions. I havent fired the 6.8x43 or 6.8RemSPC, as it is being branded, but I have been following development.

The idea of using a 30 Remington case as a foundation was one Mike Bykowski (High Performance Int'l) did years ago. He did a 6.5mm version with a 28 degree shoulder. Using the same bullets I use, he reported performance similar to the standard 6.5 PPC. However, I never heard of the round going any farther or being even considered a competition alternative in the AR15 unlike the PPC which has been considered the only real option for the AR15 whether that be a 22 PPC, 6 PPC or my 6.5 PPC.

The 6.8RemSPC is an interesting round. The bullet you are speaking of is a 115 grain HPBT (.352 BC) which has a similar ballistic coefficent to the Sierra 77 grain Match King (.362 BC). At equal velocities, the 115 grain will increase the terminal energy over the Sierra 77 MK in a pure one on one effectivness match up. However, I have heard a wide range of reports of the velocity of the 6.8mm. From the net, people have said 2600-2700 fps, but other people (who I have more knowledge of their background and I know are informed in these DOD things) have reported that it is running 2300-2400 fps from an 18 inch barrel so I am waiting on seeing reality for myself.

As a direct comparison to the .223 Rem with a 77 Grain MK, the 6.8RemSPC with a 115 grain HPBT does provide more terminal energy due to greater bullet mass provided velocity is equal, but the ballistic coefficent of the bullet is an automatic restriction for use at long ranges. To improve the long range performance of the 6.8mmRemSPC would require using something like the Sierra 135 grain MK (.488 BC). Only problem is the bullet would have to be set back in the case to magazine feed and the combined reduction in powder capacity and increase in bullet weight would have a significant reduction in velocity. I would guesstimate that IF the 6.8RemSPC is running 2700 fps with the 115 grain HPBT, that going to the 135 grain MK would drop velocities to 2400 or 2500 fps. My basis for this guesstimate is my experience testing the Sierra 142 grain MK's in the 6.5 PPC which had to be set back and were heavier as well. Another point about the Sierra 135 MK is it might not even be possible to set the bullet back far enough in the case for a magazine length load if the bullet ogive is longer then the difference between the case length and 2.255 inches.

In comparison, the 6.5 Grendel can run a bullet with a ballistic coefficent of .547-.560 from the magazine and do so at velocities ranging from 2500 fps to 2800 fps depending on barrel length and load. Now, comparing a .547 BC Lapua 123 Scenar bullet to a 115 grain bullet with a .352 BC would not even be a contest. The .488 BC Sierra 135 MK would close the physics race, but even then, a 60 BC point spread is still alot to overcome if velocity is equal.

For the military, calculating maximum effective range based on the point when the minimum terminal energy threshold is reached. The 6.5mm Lapua 123 Scenar reaches the mark at 1450 yards based on a MV of only 2600 fps which was acheived using the basic 6.5 PPC and not with the improved case capacity of the 6.5 Grendel which should add 100 fps. Using the same computer model, the 6.8mm 115 grain HPBT with a MV of 2700 fps would reach this terminal energy level at 800 yards. Yes, 800 yards is a long way out there on a shooting range, but when the target is shooting back, it becomes a whole lot closer I think most people would agree.

I am intrigued by the 6.8RemSPC. The round is an improvement over the .223 Rem from the magazine and the development team should be given credit for that. Based on everything I have gathered about the 6.8 RemSPC, even giving it the velocity benefit of the doubt, it lacks the long range legs of the 6.5 PPC or 6.5 Grendel. Both rounds have similar magazine capacities in a military version (25 rounds for the Grendel, 28 for the 6.8RemSPC) and both rounds require special magazines contrary to the misinformation that only a follower change is required to use standard .223 magazines.

Now, if the velocity is really in the 2300-2400 fps, what is the point given what a Sierra 77 MK can do in the same barrel length. While the 6.8mm will have a 38 grain weight advantage, it will have 400-500 fps velocity disadvantage.

Of course, the interesting question is "will it be commercially available?" The 6.8RemSPC round is a special forces project and development was paid for by them. In a nutshell, the special forces own the round, not the contractors. For it to be commercialy released, the DOD would have to give permission to the contractors to do so.

Given the war on terrorism and the need to not give enemies easy access to technology along with the previous heat the DOD got for selling surplus 50 BMG ammo (the DOD doesnt do that anymore), it would appear commercial release is questionable. Not to mention, it would not be very wise politically for the DOD to release it given that it was clearly intended to be a more effective killing round then the .223 Remington. I dont think the law enforcement community will let that fact go by

As a comparison, the 6.5 PPC and it commercial evolution, 6.5 Grendel, was a completly private sector development and will be released commercially at the 2004 SHOT Show. Prototypes are out there right now and are being seen and fired by people in the private and government sectors.

It is clear though, the DOD is out looking for alternatives to the .223 Remington for both the remaining service life of the AR15 platform and even for the new H&K platform if that ever comes to being with the government's financial woes and numerous other high dollar items coming into service in the same time period.

[Badger Arms]

The 30 remington has a base diameter of .422 vs. the PPC's .440. Surely it has more potential. Since .440 is the largest diameter that will feed from a 7.62x39mm magazine designed for the AR-15 (at least when stacking true double-column) then we seem to be stuck with that maximum.

How about a 358 caliber version? The 360 Badger! Use 300gr VLD bullets. This would make one HECK of a suppressed round with low pressures. Would yield greatly improved ballistics over the 300 Whisper and reduced recoil over the 50 Beuwolf.

[TX65]

Badger,

What you gain with the 30 Remington case at 43mm over a PPC at 39mm is offset by the smaller diameter of a .420 head vs a .445 head.

If you want a large caliber thumper in an AR15, Alexander Arms has a the .50 Beowulf which will push a 325 grain chunk of metal out at 2,000 fps in an 18 inch barrel.

For subsonic work, SSK Industries had a whole range of whisper rounds including the 6mm, 6.5mm, 7mm, 7.62mm and I believe a .338 Whisper that will work in an AR15.

TX65

[Badger Arms]

The 30 remington has a base diameter of .422 vs. the PPC's .440. Surely it has more potential.Sorry for this, I meant to say that your case has more potential being of a larger diameter even given its shorter Case Overall Length. My mind and fingers weren't communicating well.

On the subject of the Whispers, the 338 Whisper (version 2), you are basically beyond the 'safe' limit of necking up the 221 cartridge. The 360 Badger would have a small, but functional shoulder with positive headspace. It would have enough case capacity to give it improved supersonic performance and yet not lessen the efectiveness of the suppressor because of too much capacity. Heck, you could even shoot 9mm out of it for practice (.003" undersized bullets notwithstanding).

I don't want a large caliber thumper on the order of the 50, but I wouldn't mind a mid-bore which could be suppressed.

[TX65]

Badger,

The world I play in is 300-1000 yards so subsonic ammo is not my forte'. I would say there are lots of possibilities. Given the new 6.5 Grendel brass coming available, you would easily be able to neck up the 6.5 to a whole range of calibers up to maybe a limit of .358.

Before ordering a reamer or dies, I would wait for the public release of the final case dimensions to give JGS Tool something to work from in making a reamer.

As far barrel twist, gas port size and location, that is where you will need to experiment.

[Badger Arms]

Sounds good. I'll probably have to special order a suppressor to handle the larger diameter and greater gas volume. Wonder if I could just use 9mm and ream a 9mm AR-15 barrel? It's worth some thought.