I bought a .22 LR conversion unit at Knob creek made by CMMG.
My 22 conversion works and shoots fine, until it is time to remove it from the upper receiver.
before installing it in the upper I oiled the bolt and put some teflon grease on the outside of the rails.
I only fired 100 rounds and tried to removed the conversion unit and it was stuck.
Got it home pulled the upper off the lower and tapped it off with a brass punch.
Tried to slide the unit back and and remove it with the upper not on the gun. I still had to tap it out.
The sides of the rails are very rough could polishing them help?
The upper I am using is a JSE surplus upper. It operates correctly with the DPMS chrome BCG I use to Shot 5.56/ 2.23.
Any other ideas?