Jason762

I've got a Guntec USA upper reciever and handguard. Recently I purchased a Aero M5 lower and pin kit. The upper and lower fit together very loose. Aero advertises their lowers to accept DPMS pins and I called Guntec and they say the same thing. I'm bringing both halfs to work tomorrow to actually measure the holes but the holes in the upper are obviously a little bigger.