Any interest in the 6.5 Grendel?

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Let's also remember that Bill Alexander had hopes of government contracts, and that is why he used the AR as his platform. I still think the Grendel is a very effective and efficient round, and I will have one someday, either in an AR or a CZ. Or maybe both!
 
the military will never get rid of it purely for bureaucratic reasons, they will blow millions of dollars in these trials they have proven they have absolutely no intention of adopting a new rifle from.. even when FNs newest rifle beat all their criteria with flying colors they ended the program and left it at that... and its not like they couldnt afford to replace each and every rifle in the military 10 fold for the price of just one of their stupid jets they'll never even use

since the military isnt getting rid of that rifle it will never use another cartridge than 5.56 quite simply because both the bolt strength and magazine dimensions are pushed to their absolute limits as it is, anything made for it will have to compromise on one thing or another giving you mediocrity in return

if you want a new cartridge, a new rifle, dont waste your time waiting for the military to do it first, find what you like and then get that chambered into something that can actually handle it to its true potential
 
barnbwt said:
Speaking of which; anyone got pictures of these broken bolts? I have a theory about how they may be failing, and it has less to do with bolt thrust than geometry. Sadly, the one picture I found doesn't have a very sharp close-up of the fracture;
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The handful of pictures I've found show that the sheared lugs are always the ones next to the extractor. It is tough to infer any pattern though since there are a zillion posts discussing broken lugs and about 4 actual pictures.

Also, when you do a search you also get a lot of pics of broken bolts that are 7.63x39, 5.56, .223, etc. so to a casual researcher, or to someone who is seeking a particular outcome, it is easy to be misled into thinking this is a real problem exclusive to 6.5G. The very small number of broken lugs could just as easily and rationally be caused by a mis-aligned barrel/feed ramp than by metal fatigue from bolt-thrust.
 
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Casefull said:
I will guarantee you the majority of bolt lug failures are from using steelcase ammo.
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that makes absolutely no sense, first of all these problems existed long before steel cased ammo was even available in this cartridge, and to this date i believe wolf is the one and only to ever offer a steel case cartridge and their 6.5 grendel chambering is very anemic well below the pressure specifications of 6.5 grendel

and second of all, changing case material will not increase bolt thrust, you MIGHT be able to make a case for a broken extractor if one got stuck in a dirty chamber, but not the lugs.. the lugs break because the AR15 lugs are already pushed to their absolute maximums with 5.56
 
Shot next to a friend's 6.8 SPC today; holy cannoli, those things are crazy loud. Sounded/felt like an SBR 308 about three feet away. Bare muzzle. Somehow, his 5" 223 bumpfire upper wasn't quite as obnoxious off the side with a muzzle brake. Really suprised me how loud the 6.8 is (16" barrel, btw). Pretty accurate at 450yds despite strong, sandy winds though. If Grendel is similarly loud, I'd call it a legit drawback of these rounds; 308 trajectory, 308 noise, and nearly 308 felt recoil from a smaller/lighter package. Not quite the in-between of 223 and 308 as so often described.

TCB
 
Hmmm, well that's a bummer. I traded in my 22-250 because it was so loud. Maybe a longer barrel would tame the Grendel's bark maybe?
 
Justin, I was talking about the 7.62 39, not the 6.5 grendel. Thousands of impacts of steel on steel vs steel on brass makes a difference.
 
Maybe an auditory illusion, I dunno. Part of it was the pitch, being a larger bore, you felt it more. 223 rattles fillings, this thing rattled ribs, lol. Best description might be a x39 in pitch ('boom' not 'pop') but 223 or more in terms of 'obnoxiety factor' :D --best both worlds, I guess. Mostly just much different than what I was expecting, and depending on the pressure curve, may have been much better with a bit longer barrel.

TCB
 
A Grendel is a good choice, just because it holds more powder than about everything else - so - with enough barrel, slow ( low psi ) powder can have time to work.
6mm Hangar looks VERY good to me right now. For a bolt deer rifle...even.
To the OP - not a fan of rails of any kind, just don't like them.
Aluminum free float tube, I like. personal preference only.
 
Casefull said:
Justin, I was talking about the 7.62 39, not the 6.5 grendel. Thousands of impacts of steel on steel vs steel on brass makes a difference.
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the only real "impact" would be the bolt pushing the cartridge into the chamber, the effect this would have on wearing down lugs would be negligible at best.. its definitely a bolt thrust / bolt design issue, chamber just about any other rifle for it and it would work fine
 
Hagar uses kinda rare 30 Rem brass, though. It's also another step above even Grendel, so probably quite a handful from an AR sized platform (more of a bolt gun proposition)

TCB
 
Shot next to a friend's 6.8 SPC today; holy cannoli, those things are crazy loud.
Click to expand...

The caliber isn't particularly loud. As noted, the configuration (flash hider, brake, barrel length, etc.) may result in that particular gun being loud, but the caliber is no louder really than a .308 out of a similar barrel configuration, or 6.5 Grendel. At a naked muzzle on standard length guns, they will all be in the 163-168 db range.
 
the only real "impact" would be the bolt pushing the cartridge into the chamber, the effect this would have on wearing down lugs would be negligible at best.. its definitely a bolt thrust / bolt design issue, chamber just about any other rifle for it and it would work fine
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Have a nice day Justin...hope you get it figured out some day for your sake.
 
all this bickering about 1000 yard accuracy and I'm just over here like:

y'all want some elk steaks?
private_zpswayd3ci5.jpg
 
Llama Bob said:
There's always elves I guess...
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Yep, just as elusive as all of these broken lugs that I keep hearing about from keyboard jockeys, but not seeing any evidence or experiencing myself. In fact, your experience with 6.5 Grendel is even more elusive than that.

It's bolt thrust coupled with insufficient material. Wishful thinking doesn't change physics.
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Sorry, you have no proof. Too few broken lugs and absolutely no data backs up that it is due to bolt thrust.
 
The real culprit is geometry, and the needless insistence on placing the lugs such that they're all scrawny right there (instead of all being equal to each other, if not 'pleasingly' symmetrical. Or just shrink the extractor a hair & spare the bolt :rolleyes:

It's kind of funny that in all the years, and all the iterations of strategic reinforcement the AR has undergone, the bolt is unchanged as far as I know.

Another thought I had is that when Alexander Arms had their bolts modified to make them proprietary (I can see literally no reason for changing the headspace spec like they did) someone didn't use a properly radiused cutter or left a rough surface finish, or an un-peened or un-case-hardened finish (knowingly or not), and ended up with that portion of the bolt being a little 'inconsistent' with the rest of the part, contributing to a stress riser. There're reasons for doing things like your finish shot-peening or or case-hardening or coatings all at the same time, namely that it's really hard to be as consistent a second time.

I'm just over here like:'Well here's your trouble, right here!'
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:D

TCB
 
barnbwt said:
The real culprit is geometry, and the needless insistence on placing the lugs such that they're all scrawny right there (instead of all being equal to each other, if not 'pleasingly' symmetrical. Or just shrink the extractor a hair & spare the bolt :rolleyes:

It's kind of funny that in all the years, and all the iterations of strategic reinforcement the AR has undergone, the bolt is unchanged as far as I know.

Another thought I had is that when Alexander Arms had their bolts modified to make them proprietary (I can see literally no reason for changing the headspace spec like they did) someone didn't use a properly radiused cutter or left a rough surface finish, or an un-peened or un-case-hardened finish (knowingly or not), and ended up with that portion of the bolt being a little 'inconsistent' with the rest of the part, contributing to a stress riser. There're reasons for doing things like your finish shot-peening or or case-hardening or coatings all at the same time, namely that it's really hard to be as consistent a second time.


:D

TCB
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meh, machining will never be 100%, there are always variations in the milled part which is why machines are rating usually about 0.0001% accuracy.. that said, since not all surfaces will be perfectly matched nor will all lugs on the bolt take an equal amount of forces from the bolt thrust.. 3-4 lugs may "tripod" the rest and take the brunt of the force making the bolt in practice much weaker than it should be in theory
 
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