Results 1 to 7 of 7

Thread: CMMG .22 lr conversion issue

  1. #1
    Gunco Member zgunbear's Avatar
    Join Date
    Aug 2010
    Posts
    44
    Feedback Score
    0

    Thumbs down CMMG .22 lr conversion issue

    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?

  2. #2
    Gunco Addicted for life j427x's Avatar
    Join Date
    Oct 2006
    Posts
    9,304
    Feedback Score
    8 (100%)

    Default

    those things are sort of a PITA.

    i wouldn't think there is anything wrong with your upper unit.

    probably something in the 22 rf conversion that needs some work.

    i would check the rails to see if their bent before i did any polish work.

    lots of bad parts floating around with improper or no heat-treat these days.

  3. #3
    gunco irregular moleman's Avatar
    Join Date
    Feb 2005
    Location
    Next door to my neighbors house in Michigan
    Posts
    3,146
    Feedback Score
    3 (100%)

    Default

    I have a M261 kit and this may not apply to the cmmg kits, BUT!!! on the m261 kit the chamber insert/barrel is retained by a roll pin. When that roll pin gets worn it will allow the chamber insert to tilt slightly under pressure of the bolt once it is clear of the chamber. That causes the larger breach face end of the chamber insert to wedge itself in the upper and can be a pita to get out unless you keep the chamber adaptor straight. It only seems to loosen up evey few thousand rounds, so a 15 cent roll pin hasn't been a big issue so far. Again, that is my m261 kit and may or may not apply to the cmmg kit.

  4. #4
    Gunco Member zgunbear's Avatar
    Join Date
    Aug 2010
    Posts
    44
    Feedback Score
    0

    Default

    there is no roll pin
    CMMG tech support has not returned my calls or e-mail yet.

    I am beginning to wonder about their support

  5. #5
    Cranky Curmudgeon zoom6zoom's Avatar
    Join Date
    Oct 2006
    Location
    Virginia
    Posts
    1,483
    Feedback Score
    5 (100%)

    Default

    No advice for you... mine always just drops right out.

  6. #6
    Gunco Regular logan09's Avatar
    Join Date
    Dec 2008
    Posts
    574
    Feedback Score
    3 (100%)

    Default

    Are you a member on AR15.com? CMMG usually has great CS. If you removed the chamber adapter, there's a good chance you might have bent the rails. Also, did it come in CMMG packaging, because ceiner makes one also that has some pretty rough machining.

  7. #7
    Gunco Member zgunbear's Avatar
    Join Date
    Aug 2010
    Posts
    44
    Feedback Score
    0

    Default

    Yes it came in CMMG packing with CMMG instructions. Did not take it apart, yet. just had to tap it out of the receiver. I Emailed them again yesterday maybe they will reply tomorrow. If not I will call again. I guess I need to join a515.com. This is my first trip into AR country. Previous ly my only black rifle is a mutt L1A1.
    Like I said the kit shoots great just can't get it out of the receiver with out some persuasion

Search tags for this page

There are currently no search engine referrals.
Click on a term to search our site for related topics.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •