The key with the cam
I don’t think so, as I said in my previous post, I also have the old Colt A2 lower with the large forward pivot takedown pin. The biggest problem with using a new upper is that the hole is not just smaller but also offset from the center of the old larger hole. Which adapter are you using? There are at least two types out there that I tried and one worked better than the other.cam pin was/is loose as a goose.
I tweaked as sschevy described. Closed much more nicely. I left it with a slight bit of tension, 1/16" just before closing for a 'little' snugness.
Every time I open and close the upper, the pin moves and changes the adjustment.
Even with the lock nut pegged, that pin wiggles like a pollywog.
This concerns me. Did he f-up my lower?
This explains why I couldn't even open the upper when trying to clear it at the range.