The following is directed at the AR platform.........10 mm can be challenging at best given the wide range of chamber pressure ammunition is currently loaded in. From S&B (mild to anemic) to Sig elite (about the top end for blowback ctions to Buffalo Bore and Underwood. If you are going blowback you need to stay in the lower velocity/pressure loadings for the caliber and case belling above the rim starts to be an issue as pressure increases. One could run the hotter ammo in a blowback if they were to use a rifle length buffer tube.....and could significantly increase buffer weight beyond the 10 ounces I have been able to economically fit in a carbine length buffer.

DI opens another can of worms......for the same reason.....if ported to cycle reliably with the weaker ammo.....case expansion can still be an issue unless buffer weigth is increased. Port for the hotter loads.......and the lower power factor stuff won't cycle.......

And then we get to uppers......not all are created equal......I only recommend the Angstadt large frame lower for 10mm DI currently. Blowback I can build to run flawlessly on NFA and QC10, and if the customer insists, we can tune to run on a QC10 as well. Just not a fan of NFA and DI. The make a great product for what it is.....an economical lower for the masses......but basically the only difference in the large frame and small frame are magwell dimensions. Due to the length of the 10mm round it needs to be fed form a shallower angle to feed reliably......this is accomplished by the Angstadt Large frame.

I am looking forward to the new large frame Black Creek Precision lower due to be out soon......I was in their shop just after Shot and Darin was kind enough to let me fit a blowback 45, a DI45 and a DI 10mm upper to the lower they had taken to shot.....I thought it would be nice just from my initial visual inspection, but after pinning the uppers on and feeding live rounds I am looking forward to getting a couple in my shop and on the bench.

If I can help you with a 10mm , feel free to give me a shout at the shop......be happy to discuss the merits of the various configurations. While I'm not a huge 10mm guy, we are well into the thousands of rounds downrange in my various bench guns (each) so I'm pretty sure I can get you shooting with a carbine you'll be satisfied with. So far we have done form 6" to 16 inch" with a lot of 10" inch in between........and a small stack of 8.5 takedown guns have been built with our products by small Mfg's in both TX and Fl.

Hope this answers a few of your questions......I can be much more specific on the phone
Rudy

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