Will a 450 Bushmaster receiver and BCG accommodate any other caliber barrel? I think it has a larger bolt face and opening than the 5.56
I know the 458 SOCOM works for sure. My 450 BM upper started life as a SOCOM and when I couldn't get it to run correctly I just pulled the barrel off and replaced it with the BM. I have another upper here with a 458 SOCOM barrel on it and may just do the same thing with it. I lost patience with trying to get the SOCOM's to function right, but the Bushmaster ran perfect right from the start.
