For example, I have a 9mm SIG MPX SBR (built from a pistol) with an 8' bbl and it handles factory standard 30 round mags...
![headscratch :headscratch](./images/smilies/headscratch.gif)
Pistol Caliber Carbine Division (PCC):
1. Semi-automatic;
2. Caliber: 9mm (9X19); 357 Sig; .40S&S&W; 10mm, and .45ACP;
3. Designed to be fired from the shoulder and have a butt stock installed
4. Barrel: minimum length is 10”;
5. Maximum magazine capacity: 10 rounds (+ 1 on chamber).
Thanks!