SBR caliber?

[michael_aos]

I've got a new SBR-registered lower.

It's labeled .223, but that's not supposed to matter.

Any suggestions on an upper?

I bought it with 9mm in mind, but technically I've ALREADY got a 9mm AR that runs 100%. It's the Olympic K9GL. Accepts Glock magazines, of which I already have plenty.

I just so happen to have most of the spare-parts laying around to do a 223 build, but I'm not entirely sure why I need a short .223.

6.8SPC is supposed to be especially compatible with short-barrels.

There's always 22LR. With ammo prices what they are these days, seems like you can never have too many 22's. With that said though, my new Nordic AR-22 seems to have this venue covered.

300 Whisper maybe?

Mike

[HunterCO]

My vote since I always think about suppressing every gun I can would be .45 acp or the 300 wisper.

Atrain is in the process of building a .45 cal SBR

[Colorado Osprey]

I was thinking 45ACP also.
You already have a 9mm, so why not a 45ACP SBR?
Better yet how about 10mm?


In rifle calibers AR's if I wanted an SBR, I would want it to hit hard even at a lower velocity, maybe a 7.62x39...kinda like a cheaper version of the super-sonic 300 whisper loads.

With C-products supposedly making reliable mags, the mag reliability problem with 7.62x39 kinda went away.

[Atrain]

Yep, I am building a .45 SBR. The biggest challenge with using a standard lower is mags. The 16 round Uzi mags are big bucks now and hard to find. I only have 2 of the converted Olympic ones. Olympic keeps talking about making new ones but won't give a date. People have modified grease gun and sten mags to work. If you're considering .45 I would read through the .45 thread on the other AR site so you know what's out there and what has been done. Feel free to PM me if you have questions.