You're looking at the button on the shooters right side of the receiver. The threaded portion of the mag catch should be flush with the button.
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This is caused by high primers - a primer that's not fully seated will cause the bolt to stop before it's fully in battery and you have to po-go to clear. You may not see it except when closing the bolt on a fresh mag.Quote:
...the others were (don't know what this is called) this: I locked the bolt back, insert a fresh mag (without slapping, not overloaded) and and hit the bolt catch/release. The bolt went forward, but jammed/stopped 1/4" from battery. When I tried to lock the bolt to the rear again, it was VERY difficult. The charging handle was stuck and it was very difficult to pull to the rear.
We were providing range support for some ROTC’s that were qualifying with the M16. We had a lot of double feeds and live rounds getting trapped between the bolts and charging handles. I have no idea where they acquired the rifles but they were in bad shape. Turns out that the mag catch springs were weak and replacing the springs took care of the problems. Until we ran out of springs, then we would just turn the catch in one rotation.
OK, I looked at the mag catch button and the threaded portion wasn't flush with the button. I turned it two full rotations clockwise, but then it was protruding a bit (felt like the mag catch button had a stud in the center) so I backed it out one rotation and it's perfectly flush with the surface of the button. This is the only thing I changed (adding the Norgon ambi-catch) after sighting in the rifle. If it was causing the problem, wouldn't it manifest itself earlier in the day?
I don't understand why this will make an impact.
Have you tried some good (I.E. known quantity like Federal or Lake City) ammo to see if it feeds OK.
Hey nice pic there. Looks familiar :cool:
Seriously though this isn't an LMT issue. I created that pic the other year when my wife was having a problem with her 6920 during an Appleseed shoot using Federal XM193.
We havent been able to recreate that problem since.
At a recent carbine course, the instructor told me how he had recently bought a case of .223 that ended up giving him nothing but problems. I asked what ammo it was and he told me BVAC. I would try some other ammo and see if you are still having problems.
Yes, the search function is my friend. I read your thread, but didn't see what, if anything, you did to "cure" it.
I didn't shoot any of the BVAC ammo prior to the course, just the Federal. Thinking back, early in the day we were mostly doing single shots and slow fire. The troubles began when we started "running & gunning". I'll have to get some more Federal and see if that doesn't fix it.
Am I correct that .223 and 5.56 are the same dimensions, but 5.56 is loaded to higher pressures?
Check out this thread for your answer
I'm having trouble wrapping my mind around this, how exactly does this cause double-feeds? On my rifle the threaded post is just below flush, if I turn it one more turn the post sticks out higher than the button. Which way should I leave it? Colt mag catch and button BTW.