Since you already have a few 5.56s, I'd definitely get a 9mm. After I built my 5.56 SBR, I almost never shot my 16" guns again.What do you guys think? I've got a few 5.56 ar-15's....
Both?
If you plan on getting a 9mm suppressor then I'd get the 9... If not then I'd get the 5.56 they are pretty loud and tend to piss people off at the range that are sitting next to you but hey... I'm not a people person anyways!