This upper receiver is built to just accept Colt SMG magazines on account of its modeling within the revered Colt Sample PCC. Nonetheless, it’s very good to are aware that it may also handle Glock magazine-fed decrease receivers also. So you may have some scope here to construct a PCC https://coltsmgupper47163.fare-blog.com/26723677/new-step-by-step-map-for-colt-smg-upper-receiver