Page 2 of 9 FirstFirst 1234 ... LastLast
Results 11 to 20 of 88

Thread: Can you cite specific failures of piston AR's?

  1. #11
    Join Date
    Jun 2010
    Location
    South Florida
    Posts
    58
    Feedback Score
    0
    I had a CMMG piston upper over a Rock River lower. One day at the range the weapon stopped feeding rounds. Basically it turned into a single shot AR. When I got home and disassembled the upper I found that the piston rod return spring had jumped over it's retainer therefore failing to push the piston back into it's bore for the next shot. It was at that point that I decided piston ARs were not for me. Didn't think to take photos. Sorry bout that, they would have been interesting to look at now.
    FFL Dealer
    NRA Pistol and Rifle Instructor

  2. #12
    Join Date
    Jun 2010
    Location
    South Florida
    Posts
    58
    Feedback Score
    0
    Quote Originally Posted by Iraqgunz View Post
    Carrier tilt is actually important. Tell me what happens to the bolt if the carrier is tilting downward into the lower receiver extension?

    There are reports (I haven't seen one) of the bolt lugs cracking on some bolts.
    Thanks for posting this IG. What a shit storm I started at TOS when I mentioned this very point. It stands to reason that if the BCG is tilting at the rear it has to also be putting pressure at the bolt lugs and it's tail.
    Last edited by venuto; 02-28-11 at 19:25.
    FFL Dealer
    NRA Pistol and Rifle Instructor

  3. #13
    Join Date
    May 2010
    Location
    Michigan
    Posts
    82
    Feedback Score
    0
    Quote Originally Posted by Iraqgunz View Post
    Carrier tilt is actually important. Tell me what happens to the bolt if the carrier is tilting downward into the lower receiver extension?

    There are reports (I haven't seen one) of the bolt lugs cracking on some bolts.
    I thought the carrier tilt problem can easily be solved? So besides carrier tilt what else is the problem?

  4. #14
    Join Date
    Jan 2011
    Location
    NE TN
    Posts
    433
    Feedback Score
    0
    Quote Originally Posted by westcoastfrog View Post
    My 416 had few issues but it did have a few. First issue was when a leg of my firing pin retaining cotter pin broke off and locked my bolt halfway back. Second i had a bolt prong sheer off on the non extractor side. I continued to shoot the gun for at least a couple of thousand rounds to see how it would do and it even continued to work after the second prong sheered off...third prong sheered off and gun became a bolt action. Justmy limited experience with the 416. Would still trust ,y life to it if parts weren't so hard to get....ultimately i decided that a well maintained di m4with plenty of replacement parts was a better fit for me than a high speed gun that i couldn't maintain properly in regards to parts.
    Why the hell would you keep firing it after a bolt lug broke off? After TWO broke off?!?

  5. #15
    Join Date
    Sep 2007
    Location
    AZ
    Posts
    27,214
    Feedback Score
    14 (100%)
    I'd be more interested in actual account of WORKING PISTONS...

    I wouldn't believe them.... but I'd be interested in the accounts.

  6. #16
    Join Date
    Jan 2009
    Posts
    139
    Feedback Score
    0
    Quote Originally Posted by Iraqgunz View Post
    Carrier tilt is actually important. Tell me what happens to the bolt if the carrier is tilting downward into the lower receiver extension?

    There are reports (I haven't seen one) of the bolt lugs cracking on some bolts.
    Well, wear is only important if it contributes to a significant lessening of the life of the part, or leads to a specific failure.

    And plenty of DI guns break bolt lugs....

  7. #17
    Join Date
    Jan 2009
    Posts
    139
    Feedback Score
    0
    Quote Originally Posted by markm View Post
    I'd be more interested in actual account of WORKING PISTONS...

    I wouldn't believe them.... but I'd be interested in the accounts.
    Sarcasm, I assume?

    I have an LWRCi upper with a couple thousand trouble-free rounds through it....

  8. #18
    Join Date
    Jun 2006
    Posts
    175
    Feedback Score
    0
    Quote Originally Posted by Iraqgunz View Post
    Carrier tilt is actually important. Tell me what happens to the bolt if the carrier is tilting downward into the lower receiver extension?

    There are reports (I haven't seen one) of the bolt lugs cracking on some bolts.
    Would the floating bolt "head" due to tolerances with the bolt ring OD, carrier ID and cam pin groove mitigate any effect of limited carrier tilt (use of anti tilt buffer) on the bolt lugs?

    Bolt lugs also crack on gas guns, internal piston guns, direct impingement guns, whatever you want to call them.

    But, the recoil impulse on a piston gun is certainly different and might be more severe due to the lack of a forward impulse from the gas operation.

  9. #19
    Join Date
    Jan 2008
    Location
    AZ-Waging jihad against crappy AR's.
    Posts
    24,902
    Feedback Score
    104 (100%)
    Seriously? Think about this. If the rear of the carrier is tilting, that means that the front of the carrier (where the bolt is) is also tliting upwards which is going to put stress on the bolt as the carrier travels rearward and the bolt unlocks.

    You're right about DI guns bolts breaking. Which is why you should be even more concerned.

    Quote Originally Posted by Sttrongbow View Post
    Well, wear is only important if it contributes to a significant lessening of the life of the part, or leads to a specific failure.

    And plenty of DI guns break bolt lugs....



    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

  10. #20
    Join Date
    Nov 2007
    Location
    VA
    Posts
    7,469
    Feedback Score
    12 (100%)
    Robb Jensen has written on this site about Hk416s cracking receivers.

Page 2 of 9 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
  •