Page 2 of 4 FirstFirst 1234 LastLast
Results 11 to 20 of 32

Thread: Failure to Feed..LMT CQB MRP Piston

  1. #11
    Join Date
    Mar 2009
    Posts
    33
    Feedback Score
    0
    Thanks guys Gene e-mailed me and told me to try some heavier NATO stuff in it and let him know...he said the PMC is way under pressure and the ultramax 52 even worse....only thing is NATO stuff is hard to find and pricey!!!


    one thing if I could ask the LMT CQB MRP Piston owners to do for me... grab your AR AND SMOOTHLY AND SLOWLY pull back the charging handle in it. do you feel ANY spots in the travel that seem to have any resistance in it? mine does right after the first inch of travel the sensation FEELS like an tube with an o-ring on it being pulled through another tube with a tight spot on the middle of he travel during the pull. once i overcome the slight resistance increas the rest of the travel is smooth and of lesser resistance than at the tight sopt..the tube is not bent or dented as far as I can tell at all.
    Thats the best way to describe the FEEL travel of the buffer movement...I pulled it all apart and it seem to be in good order...the inside of the buffer tube is nice and smooth and has that funny gray coating stuff in it like the upper does where the BCG rides.

    any of yours feel that way or are they consistant all the way back to the stop?

    Thanks fellas

    Swirl.

  2. #12
    Join Date
    Nov 2008
    Posts
    214
    Feedback Score
    0
    M4super,
    Thats great advice. Use a lighter bolt with lighter ammo and a heavier bolt with heavier ammo.

    I always wonder about when they open up the gas port. If you switch to .556 ammo, you end up overgassed.

    The thing about the effects of being overgassed are that they are insidious. More wear and tear on the bolt, a bit more recoil. That is unless things are moving so quickly that the bolt goes over the top of the round its supposed to pick up, because the mag hasnt had time to move it into position.

    Either way. I like the fact that you can tune your action to the ammo by swapping around buffers.

    Don

  3. #13
    Join Date
    Jan 2008
    Location
    Denton, Texas
    Posts
    9
    Feedback Score
    0
    Quote Originally Posted by hoverp View Post
    Thanks guys Gene e-mailed me and told me to try some heavier NATO stuff in it and let him know...he said the PMC is way under pressure and the ultramax 52 even worse....only thing is NATO stuff is hard to find and pricey!!!


    one thing if I could ask the LMT CQB MRP Piston owners to do for me... grab your AR AND SMOOTHLY AND SLOWLY pull back the charging handle in it. do you feel ANY spots in the travel that seem to have any resistance in it? mine does right after the first inch of travel the sensation FEELS like an tube with an o-ring on it being pulled through another tube with a tight spot on the middle of he travel during the pull. once i overcome the slight resistance increas the rest of the travel is smooth and of lesser resistance than at the tight sopt..the tube is not bent or dented as far as I can tell at all.
    Thats the best way to describe the FEEL travel of the buffer movement...I pulled it all apart and it seem to be in good order...the inside of the buffer tube is nice and smooth and has that funny gray coating stuff in it like the upper does where the BCG rides.

    any of yours feel that way or are they consistant all the way back to the stop?

    Thanks fellas

    Swirl.
    At first, I did have some of what you described. I did a few things to smooth it out.
    1. Took the new spring I planned to use and put it in another rifle and ran a carbine course (about 700 rounds). Cleaned it, applied liberal lithium grease and reinserted into the LMT setup. You could also use a spring that has been shot a bunch in another rifle.
    2. Cleaned and generously lubed the carrier (and the new carbine buffer) after the LMT test firing and my own shooting trying to get it to run.
    3. Reassembled, then hand cycled the action (i.e. pull back the charging handle fully and let go) about 400-500 times - did it while watching TV. Just do 50 or so, rest then repeat.

    That process smoothed it out quite a bit.
    Last edited by M4Super90; 04-08-09 at 20:40. Reason: spelling

  4. #14
    Join Date
    Mar 2009
    Posts
    33
    Feedback Score
    0
    I just tried Hornady 75 Grain HPBT TAP LE and it did the same thing....single feed only and feed jams form not enough inertia comming forward...can only clear it by charging handle full to the rear and letting go. each time. 5 rounds

    H2 buffer in the gun as specified for the piston. I bought the rifle as a whole gun not a replacement upper.

    I also broke the whole thing down and all is well no grunge or crud anywhere...
    Last edited by hoverp; 04-08-09 at 20:49.

  5. #15
    Join Date
    Jan 2008
    Location
    AZ-Waging jihad against crappy AR's.
    Posts
    24,902
    Feedback Score
    104 (100%)
    I would try a different buffer or just send the rifle back to LMT and make them make it right.

    Quote Originally Posted by hoverp View Post
    I just tried Hornady 75 Grain HPBT TAP LE and it did the same thing....single feed only and feed jams form not enough inertia comming forward...can only clear it by charging handle full to the rear and letting go. each time. 5 rounds

    H2 buffer in the gun as specified for the piston. I bought the rifle as a whole gun not a replacement upper.

    I also broke the whole thing down and all is well no grunge or crud anywhere...
    Last edited by Iraqgunz; 04-09-09 at 05:44.



    Owner/Instructor at Semper Paratus Arms

    Facebook: https://www.facebook.com/SemperParatusArms/

    Semper Paratus Arms AR15 Armorer Course http://www.semperparatusarms.com/cou...-registration/

    M4C Misc. Training and Course Announcements- http://www.m4carbine.net/forumdisplay.php?f=141

    Master Armorer/R&D at SIONICS Weapon Systems- http://sionicsweaponsystems.com

  6. #16
    Join Date
    Jun 2008
    Location
    Melbourne, Florida
    Posts
    332
    Feedback Score
    0
    Quote Originally Posted by Iraqgunz View Post
    I would try a different buffer or just send the rifle back to LMT and make them make it right.

    I'm pretty much of the opinion of Iraqgunz.........if your rifle can't/won't cycle ammo, it's under warranty and LMT should take care of you. I have had nothing but good CS from LMT and Gene has been very helpful and willing to talk with me on the phone whenever I call.

    That said, if I were to still have problems shooting various ammo in my rifle (which I don't.......it shoots and functions really well with PMC, Silver Bear, and Prvi 55gr.!!!) I would not hesitate to give Gene another call tell him of my continued problems and see if he (LMT) would not agree to swap out your rifle for one that functions with all ammo. That should be the least they could do for you!!!
    God Bless and good shootin'!!!

  7. #17
    Join Date
    Mar 2009
    Posts
    33
    Feedback Score
    0

    Smile

    Quote Originally Posted by Cohibra45 View Post
    I'm pretty much of the opinion of Iraqgunz.........if your rifle can't/won't cycle ammo, it's under warranty and LMT should take care of you. I have had nothing but good CS from LMT and Gene has been very helpful and willing to talk with me on the phone whenever I call.

    That said, if I were to still have problems shooting various ammo in my rifle (which I don't.......it shoots and functions really well with PMC, Silver Bear, and Prvi 55gr.!!!) I would not hesitate to give Gene another call tell him of my continued problems and see if he (LMT) would not agree to swap out your rifle for one that functions with all ammo. That should be the least they could do for you!!!

    Any of you LMT owners out there have the slight pause /drag/resistance on the charging handle pull after about an inch and a half of travel backward? or is it the exact same resistance (other than loading up of the spring) for the whole stroke?

    Thanks,


    I have tried talking to Gene but he is always at the RANGE!!! I need a job like that...

  8. #18
    Join Date
    Jun 2008
    Location
    Edmonds, WA
    Posts
    1,845
    Feedback Score
    1 (100%)
    All of my lowers do that, 5 out of 5. LMT, Mega, and Noveske.
    Last edited by spamsammich; 04-09-09 at 13:49.

  9. #19
    Join Date
    Nov 2008
    Posts
    214
    Feedback Score
    0
    That drag is the BC engaging the hammer and cocking it.

  10. #20
    Join Date
    Jun 2008
    Location
    Edmonds, WA
    Posts
    1,845
    Feedback Score
    1 (100%)
    Quote Originally Posted by dcmdon View Post
    That drag is the BC engaging the hammer and cocking it.
    Which is why I'm very glad all of my lowers do that

Page 2 of 4 FirstFirst 1234 LastLast

Bookmarks

Posting Permissions

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