CMMG .22 LR CONVERSION UNIT difficult to remove from upper

[zgunbear]

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?

Edited April 23, 2011 by zgunbear

[Westwindmike]

I had the same problem with my CMMG unit. It got so stuck in the chamber that I had to take it to a machine shop and have them make a "tool" to "tap" it out. Beat it out was more like it. Sent it back to the dealer and he replaced it no problem. The new one slides in and out like it's supposed to. I guess they get one out of spec every now and then.

The original Ceiner units always worked better after polishing the rails. The CMMG and Ceiner both like to run very wet with oil.

Good luck with yours.

[Guest no_masters]

My friend went and bought a cmmg kit also at the knob creek also. We shot it last week and he didnt seem to have any problems with it. Ill ask him again.

[Tempest455]

I also have a CMMG (stainless) and have not had a problem with it. Probably have 500 rounds through it at this point. I would contact the mfg.

[zgunbear]

got a new one and it slips in and out like it should;d going to go shoot it monday