Grendel Evolution - AR10

[Tedward]

How about a single stack case like the Beowulf, center load and super fat with the Grendel Round. That would pack a punch in the AR-15 and everything is available but the case throat modification.

[bwaites]

I know I am probably not the right person to say this but. I'm not worried about bolts breaking since 2007 when I modified a LWRC 9310 bolt. I've run the Grendel so hard the cases swell to look like a belted magnum. Bill W. has also pushed the G very hard from the posts I read here. You may be able to get another 100fps over what Bill A posted as max loads many years ago. Because of the case length the bullets normally don't take up much of the powder space so even loaded longer than mag length I don't think you'll see more than another 50fps. The limiting factor is the max pressure usable in the Grendel case.
A bolt rifle with a chamber that is fully supported will stop the belted magnum look but the pressure is still there. Over 60 k you are taking a chance of rupturing the case.
I made a small batch of 50 -264/G barrels with big extensions and bolts a few years ago. The velocities were the same as we have always seen.
As for the mag question a 45mm long Carcano case feeds fine out of Pmags.

Guys, are you actually reading the posts? Woohoo answered the question most of you are asking. There simply is not enough space in the case to increase the powder capacity significantly. He built big extensions and bolts, and they couldn't significantly increase velocity. To significantly increase that velocity, you've got to have more horsepower room. That means that you really aren't going to get another 100FPS with a 123 unless someone comes up with a new powder which has a high density and a smooth curve.

Someone could model it, but I'm betting that to get another 100FPS with 123's you'd need another 5-10 grains of powder. You aren't getting that in the Grendel, because you simply can't load the bullet out that long!

If you are going to a larger rifle, you have that cartridge already. Either the 6.5x47, 6.5 Creedmoor, or the .260 Remington. (I find it laughably entertaining that Remington doesn't even build a rifle for a cartridge named after them!)

Going to an "AR12-13" frame is silly. You can strip AR 10's down and get them to within a pound or two of an AR15. Do you really want to spend hundreds of thousands of dollars to save that 8-16 ounces? If you want a light AR10, use a pencil barrel, carbon fiber rail, light butt stock, and go with light 6.5 Creedmoor loads. You'd have recoil close to the Grendel, with that 100FPS or so increase in velocity.

For what the vast majority of you are talking about, that would be the perfect solution. You want a hunting gun with a little more ooomph than the Grendel? .....There you go.

Please don't say, "But what if I want to shoot long range targets?" Because long range guys don't really care what our rifles weigh. Most FClass open rifles push the weight limit of 22 pounds. Its actually pretty hard to make an AR10 weigh that much. Long range shooters don't mind the weight, because they generally set their rifle up, shoot, and don't move. Its the hunters that want light, and if you are hunting with a 6.5 and think you need more than the 1-3 shots that a light barreled rig will give before it heats up enough to (possibly) change point of impact, then you need to practice more, you don't need an AR12!

The Grendel remains the optimum production cartridge for the AR15. Be happy with that. Confusing things with Grendel AR12's is more trouble than any possible benefit.

And do you really need more in a cartridge that will do this to a buffalo?

http://www.youtube.com/watch?v=CwtOBLrmLiw

[XcountryRider]

Smith and Wesson M&P10 in 308 with a 18in barrel is in the 7lb range which is less than my 18in Grendel.

[XcountryRider]

If it fit a standard AR-15 lower it would be awesome because of the price involved in ownership. We all have AR15 lowers.

[cory]

Guys, are you actually reading the posts? Woohoo answered the question most of you are asking. There simply is not enough space in the case to increase the powder capacity significantly. He built big extensions and bolts, and they couldn't significantly increase velocity. To significantly increase that velocity, you've got to have more horsepower room. That means that you really aren't going to get another 100FPS with a 123 unless someone comes up with a new powder which has a high density and a smooth curve.

Someone could model it, but I'm betting that to get another 100FPS with 123's you'd need another 5-10 grains of powder. You aren't getting that in the Grendel, because you simply can't load the bullet out that long!

If you are going to a larger rifle, you have that cartridge already. Either the 6.5x47, 6.5 Creedmoor, or the .260 Remington. (I find it laughably entertaining that Remington doesn't even build a rifle for a cartridge named after them!) But I like the Grendel! What it comes down to for me is I'd rather have a lot of ammo stocked for one chamber than a small amount of ammo for each of several chambers.

Going to an "AR12-13" frame is silly. You can strip AR 10's down and get them to within a pound or two of an AR15. Do you really want to spend hundreds of thousands of dollars to save that 8-16 ounces? If you want a light AR10, use a pencil barrel, carbon fiber rail, light butt stock, and go with light 6.5 Creedmoor loads. You'd have recoil close to the Grendel, with that 100FPS or so increase in velocity. Ounces equal pounds, and pounds equal pain. The AR12 is going to get built in a design that's going to take off eventually. I'd like to see it built around the Grendel.

For what the vast majority of you are talking about, that would be the perfect solution. You want a hunting gun with a little more ooomph than the Grendel? .....There you go.

Please don't say, "But what if I want to shoot long range targets?" Because long range guys don't really care what our rifles weigh. Most FClass open rifles push the weight limit of 22 pounds. Its actually pretty hard to make an AR10 weigh that much. Long range shooters don't mind the weight, because they generally set their rifle up, shoot, and don't move. Its the hunters that want light, and if you are hunting with a 6.5 and think you need more than the 1-3 shots that a light barreled rig will give before it heats up enough to (possibly) change point of impact, then you need to practice more, you don't need an AR12!

The Grendel remains the optimum production cartridge for the AR15. Be happy with that. Confusing things with Grendel AR12's is more trouble than any possible benefit.
Confusing things? As long as the chamber and brass aren't changed how does it confuse things? It just gives us more options.

And do you really need more in a cartridge that will do this to a buffalo? I don't need it but I want it! Haha

http://www.youtube.com/watch?v=CwtOBLrmLiw

I've responded within your text in red.

You're right outside of the 140gr projectiles the increase in velocity will be small until we get a powder designed for the Grendel. Then again to touch on the military debate, the 308 performance and 556 mass is what any and all potential replacement rounds will be compared too. That velocity increase with off the shelf powder maybe just what's needed to get to the performance and mass range the military "needs."

The biggest advantage to the AR12 will be the enlarged magwell that will allow for better magazines. Whenever I talk to someone experience with the AR15 and/or AR10 it's always the same response. "The magazine issue" well that and ammo availability, we've seen drastic improvement to that in the last 12 months with the 123gr SST and I think we'll see more improvement to that in the next 12 months. At least I hope.

[cory]

I talked to this guy who has the 6mm AR-15 and uses the Grendel/Laupa case. He has his own bolts and are like the Type 1 (.125) Headspace and made from 9310.

http://www.6mmar.com/6mmAR_New_Products.html

The benefit of the 6mm and at 2,700+fps and out to a 1,000 yards all day long. Faster, thinner design but not a Grendel.

http://www.6mmar.com/6mm_AR_Loading_Info.html

There are all of these different cartridges out there and changing the Grendel makes it not a Grendel. Same as being posted on the AR-10 Grendel Trend,

Just not the Grendel...

Changing the platform doesn't change the Grendel. The Grendel is a SAAMI spec (geometry) of the chamber and brass.

[Tedward]

Different brass in an AR-10 I would imagine. Maybe longer to hold the powder your referring too.

[cory]

Different brass in an AR-10 I would imagine. Maybe longer to hold the powder your referring too.

Negative. Unless the intent is to design a new round, 6.5x39 to a 6.5x45? Lapua has already done that.

[Tedward]

Thats not what I mean. Are you saying to use the 6.5 Grendel case we use in our AR-15's? Just hold the projectile out further and put a 140gr bullet with an OAL of 3.00? If so, I understand what your saying but then your buying a AR-10 Grendel Barrel. Seems to hard to get a regular AR-15 Grendel but if that is what you mean, then ok I guess.

[cory]

Thats not what I mean. Are you saying to use the 6.5 Grendel case we use in our AR-15's? Just hold the projectile out further and put a 140gr bullet with an OAL of 3.00? If so, I understand what your saying but then your buying a AR-10 Grendel Barrel. Seems to hard to get a regular AR-15 Grendel but if that is what you mean, then ok I guess.

Exactly! The only difference in the barrel would be we'd have to use an AR10 extension. That should be no problem. The problem is we'd need to modify an AR10 bolt, I think. Someone please correct me if I'm wrong.

[Tedward]

Exactly! The only difference in the barrel would be we'd have to use an AR10 extension. That should be no problem. The problem is we'd need to modify an AR10 bolt, I think. Someone please correct me if I'm wrong.

Now I understand your question. I'll test on an AR-10 mag but still won't matter till it can chamber the round. It might be to far back from the barrel extension. Are there any AR-10 rounds that are 3.00 OAL?
If they did modify an AR-10 bolt it sure would be beefy, they are twice as much material than the AR-15.

[cory]

Now I understand your question. I'll test on an AR-10 mag but still won't matter till it can chamber the round. It might be to far back from the barrel extension. Are there any AR-10 rounds that are 3.00 OAL?
If they did modify an AR-10 bolt it sure would be beefy, they are twice as much material than the AR-15.

I'm ignorant on the AR10 platform as I have no experience with it.

It will certainly be overkill, but it's a platform that'll allow us to find the limits of the Grendel cartridge at a relatively low price.

We only need .2" length added to the magwell. That could possibly be done by reducing the length of the trigger housing area . That's likely mean a negligible weight gain.

I think we only need .15"-.2" added to the width of the magwell to get a much improved magazine. I really wish Bill will give his remarks on that, as I guarantee you knows the optimal magwell width needed for a polymer magazine.

[SHORT-N-SASSY]

. . . If they did modify an AR-10 bolt it sure would be beefy, they are twice as much material than the AR-15.

Tell me about it!

I today received the following clarification from Colt Competition Rifle re their recent decision to discontinue the planned Colt Competition Rifle "PRO" CRG-20 6.5 Grendel:

"Pressure levels of the ammunition to obtain advertised performance were too close to those that would negatively impact the long-term service life of the product.

"The quality and strength of available parts, such as bolts and similar components, failed to meet our service standards. Overall failure of the entire package to meet the strength, performance, and service life demanded by us when building, testing, and marketing any Colt Competition Rifle product.

"The cartridge would be far more suitable for use in a larger and more robust rifle, such as a .308-size platform, than in the smaller AR15. However, the 6.5 Creedmoor is available for that platform, with substantially increased performance, albeit with the cost of increased size and weight.

"We will soon remove it from the website. All Distributors have been notified and all Purchase Orders have been cancelled."

[cory]

Tell me about it!

I today received the following clarification from Colt Competition Rifle re their recent decision to discontinue the planned Colt Competition Rifle "PRO" CRG-20 6.5 Grendel:

"Pressure levels of the ammunition to obtain advertised performance were too close to those that would negatively impact the long-term service life of the product.

"The quality and strength of available parts, such as bolts and similar components, failed to meet our service standards. Overall failure of the entire package to meet the strength, performance, and service life demanded by us when building, testing, and marketing any Colt Competition Rifle product.

"The cartridge would be far more suitable for use in a larger and more robust rifle, such as a .308-size platform, than in the smaller AR15. However, the 6.5 Creedmoor is available for that platform, with substantially increased performance, albeit with the cost of increased size and weight.

"We will soon remove it from the website. All Distributors have been notified and all Purchase Orders have been cancelled."

If only we knew of a company that wanted to produce the Grendel in a better suited platform with resources to prototype an AR12.

First we need to demonstrate the benefit of an AR12. (6.5 Grendel in an AR10)

Then if a small shop built the AR12, I'd be shocked if Colt wasn't first in line to purchase the design off of them.

[SHORT-N-SASSY]

AR-15 Bolt (left), vs AR-10 Bolt