Small Frame AR10 vs. Full Size AR10: What’s the difference?
Is the Small Frame AR10 just a condensed version of the full size AR10. That’s the question I get quite often and then answer is no, and here’s why. The Small Frame AR10 shares more characteristics with an AR15, and not because it’s identical in size from the magwell back, but more to the fact that it runs and feeds flawlessly across every AR10 caliber. The traditional AR10 has at times struggled with certain cartridges outside of .308 and bullets with a shorter overall length (OAL). There are manufacturers that have gotten some of these calibers to reliably run, but I think that has more to do with the skill and competence of that manufacturer, rather than the DPMS Gen 1 pattern design.
So what makes the Small Frame AR10 more reliable in feeding and function across every caliber you throw at it. Simple; the geometry is improved in subtle but significant ways, particularly the bore axis, which is lower on the Small Frame AR10, and that makes a substantial difference in feeding reliably. Why is that important? It has to do with the travel as the bolt returns and strips off a new round. In layman terms, the cartridge has an easier path into the chamber. The higher bore axis on the standard AR10 means the round has to travel at a steeper angle before entering the chamber. The lower bore axis on the Small Frame AR10 lends itself to creating a more linear path for the bullet to travel as it’s stripped off the magazine. It does not need to travel as high, before it redirects into the chamber. Furthermore, damage to the projectile tip is less likely because the travel is smoother. When discussing true precision shooting and getting everything you can out of a rifle and cartridge, minimizing the damage done to the tip of your projectile certainly warrants a discussion. Hollow point and ballistic/polymer tipped projectiles are very common with high-end quality match grade ammunition. Unfortunately, these projectiles are susceptible to damage during feeding. The more linear and streamlined travel of that projectile in the Small Frame AR10, because of the lower bore axis, results in less damage and more uniformity between shots.
Another example, is the .22 Creedmoor or similar cartridges that don’t quite reach mag capacity. We have done a significant amount of testing with the .22 Creedmoor and its shorter OAL of 2.64” (75 grain ELD-M) means more travel from magazine to chamber, versus a .308 Win for example. To put this in perspective, feeding issues are non-existent in the Small Frame AR10.
Now back to the original question, is the Small Frame AR10 just a condensed version of the full size AR10? Clearly it is not, but let’s say the only difference is in size. If that was the case, it still offers significant advantages in size and weight, which do matter quite a bit outside of Bench Rest shooters. To cite an example; we weighed our SF-10 .308 with a NightForce ATACR 1-8, NF mount, Rugged Suppressor (Micro 30), and ATLAS PSR Bi-Pod. It came in at a few ounces over 10lbs. That entire setup, just 10lbs.
Next blog post we’ll start deep diving into the .22 Creedmoor and why it’s hell on coyotes and deadly accurate, like sub 1/2 MOA accurate.
Thanks for reading!
We have an issue of money and compatibility. People have invested a substantial amount of resources into the older style platform, through all its diversity. For a person to shed all their tools, jigs, setups and what not, means to “lose” all that. My recommendation for people who want to go small frame would be to purchase a complete system and ditch any efforts at building. Sort of like the DPMS GII or Colt LE901. The AR-10/LR-308/SR-25 market is a complete mess. While it would be nice to have more in terms of compatibility with the AR-15 size .308, I think the shark has already been jumped. Small frame just adds ONE MORE path to choose from. Who sets the standard? DPMS? Colt? For the people who want to mill out their own receivers, where can they buy parts from? Who can mix with who? Small frame is interesting but who wants to make the leap?
I thought this system was licensed DPMS G2 dimensional.
Yes sir it is. Fully DPMS Gen2 compatible and we’ve had a licensing agreement with DPMS/Remington for almost 2 years now.
I have a DPMS Gen II 308 with the 24” bull barrel upper in 308 and given that Remington has thrown their DPMS line in the toilet even down to the level of parts support I’m curious to know if you will be offering replacement parts for poor schmucks like me who are now scrambling to build up a stash of spares. Thank you for you reply.
I really like the small frame so much better than traditional 308 platforms. Between the dpms gen2, Adams Arms small frame, Zev small frame, and now the F4 small frame you actually have compatibility across multiple manufacturers that doesn’t seem to exist in the old 308 platforms. There are multiple manufacturers of small frame barrels now as well. I personally think it’s completely worth ditching the old stuff in favor of the small frame. It reminds me of when Magpul developed mlok and everyone told them keymod was the standard and that ship had sailed…fast forward a few years and now even BCM is offering mlok. When a product makes more sense people seem to eventually take notice, but of course I could be wrong. It’s just me personal preference.