What other caliber to SBR?

[realtreehunter]

I picked up an extra lower yesterday because I have been wanting a spare and with the thought that what the heck, better go ahead in just case. Now I'm thinking Id like to go ahead and SBR it. My issue is what caliber? I already have a form submitted for a 300BLK and don't know that I want another one, I want my next BLK to be a bolt gun. What other calibers are make fun/useful SBRs? To SBR the BLK was a no brainer but with other calibers, the short barrel seems counterproductive. This would mostly be a home defense/close range hunter. In 16" guns I already have a 458 socom, another 300BLK, a 556, and then a 24" rra varmint with plans for a dpms g2 hunter or SASS(the SASS depends on auction prices ). I feel like I have things pretty well covered but with the whole 41f thing upon us I have the bug to build one more. This would most likely sit a while but i'm thinking of going on and doing it while its easier.

[Alphawolf082]

I have a 10.5" 5.56 gun that is actually a lot of fun. Hand loads which run 2855 fps in my 16" are doing 2525 fps unsuppressed and 2695 fps suppressed from it, so not as bad as I thought (and the can added MUCH more than I expected).

[IMGrunt]

9mm is a good project and great fun to shoot. 147gr subsonic loads.

[rimshaker]

If the lower is already stamped 5.56 then just put that on the Form 1. If it's stamped Multi Cal, then put 5.56 anyway since that's the most common.

You can swap barrel lengths and calibers all you want once approved. The most important thing is to get that serial# registered, and start the process well ahead of July 13.

[golfindia]

6.8 SPC.

[DoubleJ]

.458 SOCOM is pretty efficient in 12" barrel lengths due to the large bore and fast powders used. +1 for 9mm, also efficient and way cheap to shoot.

[TMD]

.458 SOCOM is pretty efficient in 12" barrel lengths due to the large bore and fast powders used. +1 for 9mm, also efficient and way cheap to shoot.

But quite a bit more $ to build.

[tXr]

Tromix's 375SOCOM, commonality with some 458SOCOM reloading components.

[wildfowler]

9mm is a good project and great fun to shoot. 147gr subsonic loads.

What he said.

[idaho.jon]

I love my 9mm ar pistol, but mostly because it takes glock mags haha. I've always thought a Grendel would be fun in a 10-12" barrel.