The genuine M4s(which is a military designation, not a corporate one) do not have the "M4" feed ramps that are in vogue on civilian rifles. They aren't part of the actual M4 specs.revolving cylinder, not sure what you're talking about. the colt upper receivers I own (all 4 of them) that are stamped "M4" all have cuts in the receiver.
The genuine M4s(which is a military designation, not a corporate one) do not have the "M4" feed ramps that are in vogue on civilian rifles. They aren't part of the actual M4 specs.
BR said:Both the M4 and M4A1 upper receiver call for M4 feed ramps since 2001. I don't know where you are getting your information from but it is wrong. The NSN is 1005-01-382-6795 for the upper receiver with M4 ramps.
Me too..I found myself trying to stick my pinky in that chamber.......Just messn' with ya![]()