pistol cartridge carbine

[Shrapnel762]

Getting my SBR situated and looks like i'm getting into this a little late (as in current events). So I got the 10.5 barrel in .223 on the way and I've been looking for something else to use on this lower. First thought was .22lr but then I found the RRA .40 S&W.
Anyway does anyone have experience with 5.5 or 7" 9mm or .40 uppers and conversions?

 

[Clicker]

I run a 7.5" Olympic 9mm upper. It uses Sten mags with a magwell adapter. Bolt is ramped vs the older no-ramped Colts, however I'm told the new Colt bolts are ramped.

Since these are blow back operated a heavy buffer helps, beyond that I love the smoothness & reduced cyclic rate the Enidine hydraulic buffers achieve.

I don't shoot any 40S&W stuff but I enjoy the 9mm AR set up immensely, great host for can too!

 

[Tigerstripe]

my 9 is really choppy. so a hydraulic buffer stops it?

 

[Clicker]

my 9 is really choppy. so a hydraulic buffer stops it?

Dramatic improvement, not quite MP5 smooth but way better than a standard buffer.

 

[Shrapnel762]

I'm liking this setup more and more but it seems pretty pricey getting everything. I keep leaning towards .300 blk because of this. If anyone wants to donate to the kyle's .40 s&w AR fund pm me