AR plastic / polymer mags for Grendel?

[cantgrowup]

Which if any AR-15 plastic / polymer mags are made for or will work with 6.5 Grendel ammo ?

[bwaites]

None in full capacity. 5-6 rounds, most.

[Schaut]

Ditto, bwaites. I emailed magpul a couple of months ago regarding making a grendel specific polymer mag. They said they couldn't do it and maintain integrety due to wall thickness and allowable space in the ar mag well. I do have some 5.56 mag puls and they will hold five rounds of grendel but the top one might pop out if you squeeze the sides of the mag. Once in battery, no problems. And, no scratches on the brass from the mag lips.

[cory]

We need an AR13. Slightly wider, longer magwell, with a slightly beefier upper, and beefier extension. Then a polymer mag would be no problem. That and pushing loads up towards 60 ksi.

[tony549]

Could the LWRC Six 8 upper, lower and its polymer magazine be used? I know this was developed for the 6.8 SPC, but the magazine should be a close enough fit for the Grendel and allow for 2.3" OAL

[LRRPF52]

Could the LWRC Six 8 upper, lower and its polymer magazine be used? I know this was developed for the 6.8 SPC, but the magazine should be a close enough fit for the Grendel and allow for 2.3" OAL

From everything I've seen, yes, it could be used. Do we really need it? No. The main interest some of us have is being able to increase overall cartridge length, getting more powder capacity. This would especially benefit other cartridges though, where the case length is too long to be able to fit high BC pills in them, like the .223 Rem, 6mm variants off of the 6.8, the WSSM family, the new .30 RAR, etc.

The Grendel is a very capable system as-is with .510 BC 123gr at 2350-2650fps depending on barrel length. Messing with seating depth is only likely to yield maybe 100fps at best on a blue moon, which would be cool in a 20-24" gun, but won't really do much for the others performance-wise. Then you have a deal where there are two types of mags, two types of COL's, two types of receiver sets.

I still think the AR12.5 makes a lot of sense as more people are going to AR's for hunting platforms, especially for the WSSM family. Right now, the 6.5 WSSM won't allow the COL you need for the cartridge in the AR15 mag well limitations. You can beat 308 and match or exceed 30-06 based cases with the WSSM's, with more efficient burn. I think they will be one of the waves of new hunting options based on the AR15, but a longer magwell is needed, a much larger bolt, beefier upper, enlarged ejection port, and longer mags for COL. The WSSM's currently fit in standard AR15 mags as a single stack, but need modified followers and feed lips. Barrel extension needs a center feed ramp.

[Bill Alexander]

The typical velocity increase is given in a empirical form as 1/4 of the change in case volume.

Example: Let us assume that moving the bullet from an OAL of 2.250" to 2.30" yields an additional 5% in volume, the resulting velocity increase will be 1.25% of 2620 fps or 32 fps in a 24" barrel system.

I am reserved as to the need for a bigger platform. The idea that underpins the Grendel is that it would fit and feed in an AR15 chassis. Thus existing firearms may be rendered more versatile rather than obsolete. If one is to entertain a larger envelope one should remove oneself from the constraints that are intrinsic in the Grendel. Should we then consider a 7x47 on a 0.475" rim and shorten the AR10

I am equally reserved about the long term durability of polymer magazines. The thick wall systems seen in Russian manufacture where the walls are 0.100" or above have proven themselves but this is precluded within the confines and format of the AR15.

[NugginFutz]

Thanks, Bill. I've often wondered what the yield would be for a given increase in case capacity.

As to the poly mags: I'm having trouble seeing why the high anxiety about getting a polymer mag for the Grendel exists, other than having a lighter weight mag. My Hornady brass, described as softer than the Lapua or AA alternative, is showing no abuse that I can attribute to my evil metal magazines. (I run ASC and AR-Stoners.) I have not run anywhere near the round count through my steel mags that some here have described.

Would someone humor me and please post a picture or two of their brass, showing the marring they find objectionable? I've got nothing better to do this weekend, other than wait for this annoying kidney stone to pass.

[cory]

Thanks, Bill. I've often wondered what the yield would be for a given increase in case capacity.

As to the poly mags: I'm having trouble seeing why the high anxiety about getting a polymer mag for the Grendel exists, other than having a lighter weight mag. My Hornady brass, described as softer than the Lapua or AA alternative, is showing no abuse that I can attribute to my evil metal magazines. (I run ASC and AR-Stoners.) I have not run anywhere near the round count through my steel mags that some here have described.

Would someone humor me and please post a picture or two of their brass, showing the marring they find objectionable? I've got nothing better to do this weekend, other than wait for this annoying kidney stone to pass.

I think it's more of a want for a lighter cheaper magazine.

[cory]

The typical velocity increase is given in a empirical form as 1/4 of the change in case volume.

Example: Let us assume that moving the bullet from an OAL of 2.250" to 2.30" yields an additional 5% in volume, the resulting velocity increase will be 1.25% of 2620 fps or 32 fps in a 24" barrel system.

I am reserved as to the need for a bigger platform. The idea that underpins the Grendel is that it would fit and feed in an AR15 chassis. Thus existing firearms may be rendered more versatile rather than obsolete. If one is to entertain a larger envelope one should remove oneself from the constraints that are intrinsic in the Grendel. Should we then consider a 7x47 on a 0.475" rim and shorten the AR10

I am equally reserved about the long term durability of polymer magazines. The thick wall systems seen in Russian manufacture where the walls are 0.100" or above have proven themselves but this is precluded within the confines and format of the AR15.

While a longer COL for the 140gr projectiles would be great, I was more leaning towards a lightly beefier platform that would allow us to push pressures to the 59-60ksi range. Loading for the 123gr projectiles I've still got case capacity to use.

Bill what velocity increase do you think we'd see with an 8-10ksi increase?

[stanc]

Then you have a deal where there are two types of mags, two types of COL's, two types of receiver sets.

I don't see that as being a problem. It looks to be only a matter of personal preference, just as it is with the 6.8 crowd, and has no downside.

[stanc]

I think it's more of a want for a lighter cheaper magazine.

I thought it was about getting a magazine with consistent quality and reliability? There have been many complaints regarding those issues with the stainless steel mags.

[Tedward]

I think it's more of a want for a lighter cheaper magazine.

As for wanting a lighter cheaper mag, they get lighter once you fire one round. The difference in weight is so insignificant that if your hunting with a 5 round mag, it will be much lighter than the 10 round I use when at the bench. I don't use anything longer because I put 9 in the 10 round mags to have 3 sets of 3 shot groups. Also for weight in the mag, you add much more weight with scopes and all the do-dads so cut back there before the most important part of the gun, well second. Or a shorter barrel...

As for cheaper, I think $12 to $13 is pretty cheap (less expensive). P-mags and Troy are are more expensive and cheap (Quality) so I don't even like them for my 223/556, they flex and I actually like other manufactures of poly mags like TAPCO Intrafuse and Thermold. The TAPCO and Thermold are thicker and don't flex (bulge).

Some one said the ASC or C-products make noise with them in there pockets walking thru the woods hunting. I packed my 5 round mags the other day after reading that and put 4 bullets (that is all that will fit) and shook the hell out of it. I didn't hear anything right next to me ear. I guess if you have change in your pocket you might confuse the two noises.

Anyhow, Custom Mags like AA has made for there Beowulf and 17HMR might need Bill to look at making a custom Mag for the Grendel.

Any thoughts on that Bill???

[Tedward]

We need an AR13. Slightly wider, longer magwell, with a slightly beefier upper, and beefier extension. Then a polymer mag would be no problem. That and pushing loads up towards 60 ksi.

Thats the AR-10 and maybe just make another special mag. But is someone is bored, an entire new configuration with out a magazine that hangs down would be best. I saw one the other day that was an upper and ejects thru the AR-15 magwell. The mag sits on top of the barrel length wise. Have no clue of what it was but a new idea of feeding ammo and development is what is needed. People are working on that I think and some are already out there so a AR-13 doesn't seem feasible....to me at least, go all the way, don't copy and try to finagle a fix for mid-size...
my $.02

[superfred]

Thats the AR-10 and maybe just make another special mag. But is someone is bored, an entire new configuration with out a magazine that hangs down would be best. I saw one the other day that was an upper and ejects thru the AR-15 magwell. The mag sits on top of the barrel length wise. Have no clue of what it was but a new idea of feeding ammo and development is what is needed. People are working on that I think and some are already out there so a AR-13 doesn't seem feasible....to me at least, go all the way, don't copy and try to finagle a fix for mid-size...
my $.02

I think you are looking at a AR-57 based on your description. AeroPrecision essentially made a pet project to mount a P90 on a AR-15 lower.
Making tooling for designing a new mag and cartridge along with a entirely new upper is not cheap. Fortunately for the AR57 guys, the P90 already exists, and all they need to work on is the new upper receiver. It seems like a interesting yet odd concept, unbullpuping a bullpup.

[Drifter]

Some one said the ASC or C-products make noise with them in there pockets walking thru the woods hunting. I packed my 5 round mags the other day after reading that and put 4 bullets (that is all that will fit) and shook the hell out of it. I didn't hear anything right next to me ear. I guess if you have change in your pocket you might confuse the two noises.

I doubt that anyone meant that the metal mags rattle internally. It's probably that anything coming in contact with metal will be noisier than polymer, and / or metal mags that fit loosely in the weapon tend to make noise at inopportune times.


In the grand scheme, I don't fully understand the fixation with polymer mags. But I will admit that when I head out the door with a 556 AR-15, I always grab polymer mags.

[montana]

Do we need a new LWRC type six 8 lower receiver that uses a new Pmag that holds 30 rounds of 6.5 Grendel ammo that would not be compatible with other 6.5 - 25 round magazines ? A definite no. Would I like one and pay for one? --- An absolute YES. Viva la choice.

http://www.youtube.com/watch?v=uoX68gSOfsA

[Bill Alexander]

Magazine tooling is simply expensive. I have a design for a polymer type Grendel magazine but the original production route fell through. We are not neglecting the Grendel magazine as I view this as the weakest link in the Grendel weapon system. There is a need for a well made and reliable magazine. As I write I have the design proposal on my desktop.

[cory]

I thought it was about getting a magazine with consistent quality and reliability? There have been many complaints regarding those issues with the stainless steel mags.

I defer to your opinion. I believe it's more accurate then my initial assessment.

I think you are looking at a AR-57 based on your description. AeroPrecision essentially made a pet project to mount a P90 on a AR-15 lower.
Making tooling for designing a new mag and cartridge along with a entirely new upper is not cheap. Fortunately for the AR57 guys, the P90 already exists, and all they need to work on is the new upper receiver. It seems like a interesting yet odd concept, unbullpuping a bullpup.

If we're talking about forged lowers and uppers I agree it'd be far to expensive. However, billet uppers and lowers should only require a new machining program.

I doubt that anyone meant that the metal mags rattle internally. It's probably that anything coming in contact with metal will be noisier than polymer, and / or metal mags that fit loosely in the weapon tend to make noise at inopportune times.

In the grand scheme, I don't fully understand the fixation with polymer mags. But I will admit that when I head out the door with a 556 AR-15, I always grab polymer mags.

When I fully load my 25rd mags there often seems to be a round in the magazine that isn't static, and thus will rattle as the magazine shakes. I believe that's what they're referring to.

[Tedward]

I think you are looking at a AR-57 based on your description. AeroPrecision essentially made a pet project to mount a P90 on a AR-15 lower.
Making tooling for designing a new mag and cartridge along with a entirely new upper is not cheap. Fortunately for the AR57 guys, the P90 already exists, and all they need to work on is the new upper receiver. It seems like a interesting yet odd concept, unbullpuping a bullpup.

Thats what it was, AR-57. I just glanced at it with a guy from work but something different for sure...