jmorris
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CZ finally offers the 527 in 6.5 Grendel
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Llama Bob
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Someone on there is smoking the really cheap crack. Staying within SAAMI spec, their 6BR velocity is about right, but the fastest I'd sign up for with the 6.5G and that bullet is 2470 ft/s. To hit 2760 ft/s with the 130gr. JLK, you'd need to be almost 15KPSI over SAAMI max pressure.
The 6mm Dasher of course outperforms the 6mm BR by a sizable margin and adds another 150 ft/s onto the 6BR's already superior performance.
This is a common thread in 6.5G discussions - the actual performance of the cartridge is so pathetic that people just publish made-up values from some supposed hot-rodding process, which inevitably is some combination of dangerous and/or pure fiction.
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1stmarine
Member
Darn. I got the nasty flu but this doesn't stop me for following up on my favorite threads.
After extensive testing with the Grendel I don't think that anyone will not able to push a 130gr bullet past 2550-2,600fps w/o ruining the cases no matter what barrel or powder.
The main reason I got the 6.5BR in for the AR15 was to improve precisely those kind of loads like the 130gr partition. It cannot be done with a short case other than a BR,
BRX or then a WSSM wildcat obviusly but those are a lot more involved specially for the AR15.
This doesn't mean the 6.5G/LBC is a bad round. It works really well with 100gr solids and bonded for hunting in similar way the 6.8SPC screams with 85gr-95gr solids.
For paper punching at long range works too but there are many others. Even the 6.5G simply necked down to 6mm is a significant improvement in long range ballistics over
the 6.5G parent w/o doing much. A really simple wildcat.
Like Llama bob said, the big issue in the Grendel and x39 with the AR is to make sure one finds reliable bolt groups that do not break.
It is only recently we are starting to see more ARs with strengthened beefed up bolts or dedicated bolts and extensions but there has been always the option to simply invest
in an AK, SKS or other carbine, ideally longer than 16" for better speeds.
The original Grendel numbers were a tad inflated by B.Alexander and that is what also gave some confusion and bit optimistic expectations. After a lot of chatter back and forth
these were adjusted and people now got to more realistic expectations.
I think everyone is doing the same thing trying to sell so there is always difference between the data from the marketing guys and the real life tests.
This is another reason what made the 6.8spc a very attractive and powerful option for the ranges people normally hunt. Reliability has not been an issue with the 6.8 and reloading
to the full potential yields very good performance not found in the milder factory ammo.
Again the 6.5G round is a substantial improvement in ballistics over the baseline. For some people this means they can shoot factory ammo and then use that brass if they want to reload hotter or more
specialized loads included the bolt action. For other people the drivers are a more affordable and plentiful round like the x39 including cheap steel and use the brass for some specialty loads.
Shooters who like to shoot somewhat flat (lets say the 2,700ish speed at the muzzle with .4'ish G1 ballistics) these are not the calibers although some reasonable compromises and something
interesting can be done with the 100 and 100gr solids. Also the x39 can put some nice momentum with 150gr bullets at moderate ranges. Something handy for larger game given speeds
do not fall too low.
The 6.5G is a nice round for what it is just like the x39. Interestingly both are also perfect donors for easy wildcats that provide substantial advantages over the original calibers
w/o investing a lot and obviously depending on the intended use or specialty. the 6mm-Grendel and the 35 gunner and good examples. There are a few others obviously.
But also in their original form they have a lot of nice options for people who like to research projectiles and loads and test everything.
Ballistics arguments can go on and on for hours and days as they are a fundamental part of our shooting culture and great entertainment over a camp fire.
But in the end, like any other science based on physics, in order to gain something we have to give up something. We can also throw in there popularity due
to marketing or earned merits, availability and costs.
In the ideal world I would love to have a round with the size, weight, recoil and cost of the 22LR and the performance of a win mag. But we know the world of ballistics and physics doesn't work
that way. The more you want the more you pay one way or another.
After extensive testing with the Grendel I don't think that anyone will not able to push a 130gr bullet past 2550-2,600fps w/o ruining the cases no matter what barrel or powder.
The main reason I got the 6.5BR in for the AR15 was to improve precisely those kind of loads like the 130gr partition. It cannot be done with a short case other than a BR,
BRX or then a WSSM wildcat obviusly but those are a lot more involved specially for the AR15.
This doesn't mean the 6.5G/LBC is a bad round. It works really well with 100gr solids and bonded for hunting in similar way the 6.8SPC screams with 85gr-95gr solids.
For paper punching at long range works too but there are many others. Even the 6.5G simply necked down to 6mm is a significant improvement in long range ballistics over
the 6.5G parent w/o doing much. A really simple wildcat.
Like Llama bob said, the big issue in the Grendel and x39 with the AR is to make sure one finds reliable bolt groups that do not break.
It is only recently we are starting to see more ARs with strengthened beefed up bolts or dedicated bolts and extensions but there has been always the option to simply invest
in an AK, SKS or other carbine, ideally longer than 16" for better speeds.
The original Grendel numbers were a tad inflated by B.Alexander and that is what also gave some confusion and bit optimistic expectations. After a lot of chatter back and forth
these were adjusted and people now got to more realistic expectations.
I think everyone is doing the same thing trying to sell so there is always difference between the data from the marketing guys and the real life tests.
This is another reason what made the 6.8spc a very attractive and powerful option for the ranges people normally hunt. Reliability has not been an issue with the 6.8 and reloading
to the full potential yields very good performance not found in the milder factory ammo.
Again the 6.5G round is a substantial improvement in ballistics over the baseline. For some people this means they can shoot factory ammo and then use that brass if they want to reload hotter or more
specialized loads included the bolt action. For other people the drivers are a more affordable and plentiful round like the x39 including cheap steel and use the brass for some specialty loads.
Shooters who like to shoot somewhat flat (lets say the 2,700ish speed at the muzzle with .4'ish G1 ballistics) these are not the calibers although some reasonable compromises and something
interesting can be done with the 100 and 100gr solids. Also the x39 can put some nice momentum with 150gr bullets at moderate ranges. Something handy for larger game given speeds
do not fall too low.
The 6.5G is a nice round for what it is just like the x39. Interestingly both are also perfect donors for easy wildcats that provide substantial advantages over the original calibers
w/o investing a lot and obviously depending on the intended use or specialty. the 6mm-Grendel and the 35 gunner and good examples. There are a few others obviously.
But also in their original form they have a lot of nice options for people who like to research projectiles and loads and test everything.
Ballistics arguments can go on and on for hours and days as they are a fundamental part of our shooting culture and great entertainment over a camp fire.
But in the end, like any other science based on physics, in order to gain something we have to give up something. We can also throw in there popularity due
to marketing or earned merits, availability and costs.
In the ideal world I would love to have a round with the size, weight, recoil and cost of the 22LR and the performance of a win mag. But we know the world of ballistics and physics doesn't work
that way. The more you want the more you pay one way or another.
rayatphonix
Member
Could someone explain why the bolts and extractors continually break for the Grendel, but not for the 6mm br? The 6mm br has a larger rim diameter than the Grendel.
1stmarine
Member
The 6BR bolts are oversized with proprietary extensions (larger radius and more meat around the lugs) whereas the early 7.62x39 and Grendel were simply opened up bolt faces
but with the same lugs and extensions as the 223. Same thing happens with the original 458 socom. you have to keep pressures down or they will break.
Here you can see an AR15 BR bolt 62K psi certified vs. a 223. Sorry I don't have a pic of the LBC/grendel or x39 bolt to show...
1stmarine
Member
Thanks. Feeling a bit better. had some hot soup and ate 1/2 can of jalapeños. Talking bout hot loads! lol
If i get home tonight ill post a picture of the grendel and .458 bolt. The lack of meats most obvious on the .458, which has the same rim dia as the BR.
Are there any "production" BR barrel bolt sets Or are they all special order items?
Are there any "production" BR barrel bolt sets Or are they all special order items?
Well thqts one way to cure the flu LAWLZ!
CoalTrain49
Member
If that's true why is Anderson Arms building uppers for it? Are you saying they are knowingly selling a product that breaks bolts, breaks extractors and doesn't reliably feed? Care to elaborate?
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1stmarine
Member
Those were special order from AR15performance.com. I got the 6.5BR and others from them too. Awesome products.
Later they developed a 270 too. I didn't get into that one. I cannot keep up as it is.
I think they might have a new one coming out but not sure. This has been the biggest problem with the BR and other derived from 308 in the AR15, how to get
strong bolts for the larger bolt face. That is why the 6.8 is so attractive as-is or even as donor for some nice wildcats.
Or people simply get into a lighter 308 and get whatever variant as soon as it fits in the 308 type magazines.
Panzerschwein
member
Very cool. About time they offered it in this gorgeous round.
Llama Bob
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Well, first of all I don't care about Anderson Arms the way you seem to. But looking at their website, they provide essentially no information on their 6.5G BCG - materials, MP testing, headspace, etc. If the reviews are to be believed (and they may well be wrong) it's a "type II" bolt.
In order to understand what that means, you first need to know that the 5.56 as-issued in the M16 and M4 already has a problem with breaking bolts. It's right on the hairy edge, resulting in the military specifying special steels and MP testing. The Grendel makes this worse on three fronts:
1) the larger rim diameter requires material be removed from the bolt
2) the larger rim depth requires material be removed from either the bolt or the extractor
3) the larger case head increases bolt thrust for the same pressure
The Grendel also makes the situation better by reducing the max pressure from 62KPSI to 52KPSI (both SAAMI). With all these changes, the situation you have is a 13% higher bolt thrust with the Grendel comparing SAAMI max loads. In reality the situation is worse though, because the military doesn't load to SAAMI max on 5.56. They stop at about 55KPSI (m855) specifically because of observed bolt breakage with hotter loads. So a SAAMI-max 6.5 Grendel actually has 28% more bolt thrust than the "bolt safe" military loads. And of course the bolt is weakened due to 1) and possibly 2) above.
The situation with 2) is where the "type I" vs "type II" issue comes in. The extra space for the larger rim depth has to come from somewhere. It can either come out of the bolt body (type II) or the extractor (type I). So now if we believe the reviews, what Anderson is selling is a bolt that will not break extractors, but is even more at risk of breaking the bolt than type I (which is already greatly compromised due to the rim diameter and increased bolt thrust). So yes, Anderson Arms is quite likely selling a part prone to breakage, and favoring the more dangerous of the two failure modes from the shooter's perspective.
The solution to all this would have been to either use a case of similar capacity with a smaller head (as the SPC development did) which would both reduce bolt thrust and retain material in the bolt or do a custom larger bolt head and extension like the ones 1stmarine posted pictures of. Unfortunately both of these solutions eluded Bill Alexander (the phrase "amateur hour" comes to mind) and the 6.5 G is now mired in a mess from which it seems unlikely to recover.
Anderson responded,
"first of all I would like to thank you for the inquiry for our new 6.5 Grendel. I am going to try an answer all your questions best as possible. Ok here we go. We are using the 6.5 grendel #1 Reamer which has the 0.295 neck. The rifling is Button rifling The barrels are made of 4140 chrome molly steel. The bolt is made of 9310 steel and are MPI tested. I hope this all helps let me know if there is anything else I can help with. Thank you for your time and support."
Thats a reply from Anderson to a members query on the Grendel forum (no im not a member, quick Google) link to thread here http://www.65grendel.com/forum/showthread.php?11992-Anderson-Arms-is-building-Grendel-Uppers-now
So that gives 9130 for the bolt and MPI testing, flip side is they say in the reply that they are using a G1 chamber, but that dosent match with the bolt depths listed later in the thread or on Anderson site. Could just be a typo as well.
The low(ish) cost Radical i have is the .137 bolt depth, 9130, hpt/mpi tested, i dont think ive seen the shallower bolt face on anybodys site for a while now, find a few on ebay tho.
I run my gun pretty hard, not alot of rounds thru it tho, Im interested in seeing how long the bolt will last. I was always under the impression bolts were considered "disposable" parts in an AR, is that true or are they pretty much permanent ?
"first of all I would like to thank you for the inquiry for our new 6.5 Grendel. I am going to try an answer all your questions best as possible. Ok here we go. We are using the 6.5 grendel #1 Reamer which has the 0.295 neck. The rifling is Button rifling The barrels are made of 4140 chrome molly steel. The bolt is made of 9310 steel and are MPI tested. I hope this all helps let me know if there is anything else I can help with. Thank you for your time and support."
Thats a reply from Anderson to a members query on the Grendel forum (no im not a member, quick Google) link to thread here http://www.65grendel.com/forum/showthread.php?11992-Anderson-Arms-is-building-Grendel-Uppers-now
So that gives 9130 for the bolt and MPI testing, flip side is they say in the reply that they are using a G1 chamber, but that dosent match with the bolt depths listed later in the thread or on Anderson site. Could just be a typo as well.
The low(ish) cost Radical i have is the .137 bolt depth, 9130, hpt/mpi tested, i dont think ive seen the shallower bolt face on anybodys site for a while now, find a few on ebay tho.
I run my gun pretty hard, not alot of rounds thru it tho, Im interested in seeing how long the bolt will last. I was always under the impression bolts were considered "disposable" parts in an AR, is that true or are they pretty much permanent ?
Llama Bob
member
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The military wanted to see at least a 20,000 round life out of a bolt. So basically they wanted it to last as long as the barrel. That was with m193 (52KPSI) though so in the field they're probably doing worse shooting mostly m855.
Using 9130 over Carpenter 158 is probably a modest improvement, but not a huge one. I've heard maybe a 5-8% increase in allowable bolt thrust.
Using 9130 over Carpenter 158 is probably a modest improvement, but not a huge one. I've heard maybe a 5-8% increase in allowable bolt thrust.
1stmarine
Member
Regarding the beefed up bolts in 9130 there has been a substantial improvement imo. I don't think it is something you want to run
super hot all the time but so far with the hottest loads have been holding together whereas previous designs would be already broken.
I have only tested ARP and young manufacturing bolts with the extra radius so I don't know about others.
We can almost certainly say the military will never adopt a cartridge with a pronounced shoulder angle. They have never done that for
obvious reasons and there is no indication they are going to change their long established directives now.
The ultimate solution is a custom extension whit the bolt like below.
I am not sure about Anderson or others but IMO a long lasting solution for x39 and grendel bolts in the AR15 can be found here...
http://ar15performance.com/grendel___misc_barrels
I hope this helps.
super hot all the time but so far with the hottest loads have been holding together whereas previous designs would be already broken.
I have only tested ARP and young manufacturing bolts with the extra radius so I don't know about others.
We can almost certainly say the military will never adopt a cartridge with a pronounced shoulder angle. They have never done that for
obvious reasons and there is no indication they are going to change their long established directives now.
The ultimate solution is a custom extension whit the bolt like below.
I am not sure about Anderson or others but IMO a long lasting solution for x39 and grendel bolts in the AR15 can be found here...
http://ar15performance.com/grendel___misc_barrels
I hope this helps.
Yeah, I agree custom/semi custom bolt and extension like those are probably the best answer. Im finding im not a huge are AR fan, but ive got one now so I'll probably keep experimenting and thats the route ill take. Ive asked CZ about the strength difference between the mini and full size action, id be mildly surprised if i get a direct answer but im still looking forward to the reply.
CoalTrain49
Member
I don't even own an AR and have no interest in Anderson Arms.
What I'm trying to figure out is why someone like yourself would spew so much hate on a particular cartridge. The Grendel seems to be your voodoo doll. Lots of people like it and are buying rifles that use it. Very few cartridges get picked up by the military so that doesn't necessarily make them a bad cartridge. If the military wanted that cartridge they could spec it out and I'm sure some company could make it work in an AR. Much bigger engineering problems are solved everyday in the private sector. There probably hasn't been that much work done to resolve the issues that you posted about because it looks like the military isn't interested in replacing the 5.56 anytime soon. If they were the cartridge would probably look a lot like a Grendel. So now the only market is civilian and it looks like the Grenel is doing rather well there. Everyone knows that a new cartridge has to be adopted by an ammo mfg. company and a firearms mfg. company to be successful. Hornady, Tula, PPU and Federal have all signed on. CZ (huge) and Howa are both building rifles for it. It's beauty is the action is 12% shorter than the typical short action, producing a lighter rifle. If you can't understand that then there's no point in trying to drive round pegs into square holes.
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Has been know to result in broken extractors.....yes i think im funny
CoalTrain49
Member
I would be interested in that myself. I own both CZ and Howa rifles and would like to evaluate both before I bought a 6.5 Grendel. Thanks for looking into that.
Llama Bob
member
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Except as already well documented, they managed to make a heavier and bigger rifle than the competition. Whoopsie
I think if I were gonna get a semiautomatic rifle in one of these little cartridges, I'd petition ruger for a mini 26 or get a custom built mini to do the job. Then I can enjoy the mini, the Grendel, and the fun all at the same time. Till then, it is what it is I guess. First big semi will be something with just a bit more oof though.
Yeah ive considered a mini conversion, but for the .458 lol. Im not sure how much stronger the mini would be than the AR. It seems like it has big lugs but the reciever recess are fairly small due to the short bolt lift.
ASI does offer the grendel as a conversion so i may be way off base.
ASI does offer the grendel as a conversion so i may be way off base.
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