The "McClane" from KAK industries

[yuppiejr]

The KAK / McClain Youtube video put the PMC 147 grain FMJ ball bullet across the chrono @ 2250 FPS. That's the same as a 7.62x39 123 grain FMJ or a 300 blk running 125 grain FMJ pills in the same length barrel. The .308 will still have a slight advantage in terminal ballistics, but recoil is about 2.5x greater with the .308 and the muzzle flash + climb will be significantly greater.

If a guy has an investment in the AR10 platform and wanted a shorter/pistol style rifle with which to interchange mags & ammo why not? I'm mulling over adding a 6.8 SPC AR pistol to the collection down the road to share mags + ammo with it's 18" safe-mate for those times I end up deer hunting in a slug zone and don't want to haul out the 12 gauge. To each their own, right? There are plenty of guys running around with 5.56 NATO/.223 SBR-pistols because of the ease of mag/ammo interchange with their rifles, though the performance of a 5.56 NATO/.223 cartridge out of a short barrel isn't exactly rocking anyone's world...

[yuppiejr]

Also, related-unrelated note, after watching the guy in the KAK video SHOULDER his pistol I did some research and thought this recent note from the ATF on the topic of the Sig Brace (featured on the KAK pistol) or otherwise shoulder firing an AR pistol was interesting, and is really what is pushing me toward doing an AR pistol:

http://www.gunsandammo.com/2014/04/04/a ... tol-brace/

[Squib Joe]

I'm waiting for somebody to come out with a brace that isn't quite so fugly

Hello, Magpul?

[Rip Van Winkle]

Also, related-unrelated note, after watching the guy in the KAK video SHOULDER his pistol I did some research and thought this recent note from the ATF on the topic of the Sig Brace (featured on the KAK pistol) or otherwise shoulder firing an AR pistol was interesting, and is really what is pushing me toward doing an AR pistol:

http://www.gunsandammo.com/2014/04/04/a ... tol-brace/

http://www.gunsandammo.com/files/2014/0 ... 900021.jpg

http://sigsauer.com/upFiles/proshop/pro ... Detail.jpg

This is the part that always bothers me about these types of things.

Further, certain firearm accessories such as the SIG Stability Brace have not been classified by FTB as shoulder stocks and, therefore, using the brace improperly does not constitute a design change.

In other words they can be reclassified with the stroke of a pen, and without warning, you become an instant felon.

[Bearcatrp]

I chose the 308 platform due to being invested in 308 already. Didn't want to go into another caliber. I think you folks would be surprised on the recoil of mine. I was a bit shocked myself. I spent months reading different forums with posted ATF letters before I jumped in. One hell of a headache deciphering. I think 10.5 inches for 308 is the smallest I would recommend to anyone wanting a "pistol" AR. The flash can is awesome on this. Directs flash and noise forward. Sure, its possible ATF reverse there rulings on this but doubtful. A big company as SIG probably has enough congressman in there pockets to stop any reversal.

[Bearcatrp]

Another clip of a full 25 rd mag dump. Not allot of barrel rise.
https://www.youtube.com/watch?v=IV__aA6pmAU

[yuppiejr]

Further, certain firearm accessories such as the SIG Stability Brace have not been classified by FTB as shoulder stocks and, therefore, using the brace improperly does not constitute a design change.

In other words they can be reclassified with the stroke of a pen, and without warning, you become an instant felon.

Fair point, though one would hope that Ex Post Facto would effectively apply since an owner could provide documentation that the ATF had published a statement indicating the classification prior to it's purchase but before the change in classification took place.

I'd personally choose a cartridge designed for short barrels if I were doing an AR pistol, an 8-10" in 6.8 SPC with the SIG brace and LER scope or red-dot would be wicked deer medicine on the in-laws farm, and I'm already invested in the caliber for my "up north" deer-black bear rifle with an 18" tube.