I was looking at what's being billed as a "vintage XM4" complete upper a guy has for sale. I figure the upper might actually be from a Colt 727 conversion kit, and I'm trying to determine whether its something I want to pursue.
I noted that the FH was installed with a crush washer. My recollection was that the Colts I've seen from the late 80's through mid-90's featured peel washers.
Anyone know when Colt made the switch?
