742 jammaster help

corvidae

Can anyone tell me where to look for the "saw teeth"? I've read in previous posts that there are 5 chunks of metal missing form the reciever guide when they start to go. I had mine jam this weekend. It was darn dirty so i chauked it up to that for now...

Der Gebirgsjager

Wow---we've beat this one to death over the years, and I'm certain that a search of the forum archives would turn up more than you'd want to read in an evening. I'm going to run through it again in as concise a manner as possible. The bolt has two major parts. The forward part has multiple locking lugs that mate into recesses in the rear of the barrel. When the rifle is fired the front portion of the bolt recoils backward into the rear portion of the bolt and turns and telescopes into it because there are two hardened pins on each side in zig-zag grooves that force it to do so. The pins are harder than the grooves (but it wouldn't matter much if they weren't, because something will eventually wear anyway) and eventually the grooves wear and allow the telescoped front end of the bolt to turn farther in its collapsed position than the designers intended. This puts the multiple locking lugs on the front portion of the bolt in contact with the inner top of the receiver at the rear of the stroke, and eventually they begin to cut grooves into the top of the receiver (inside). The eventual result is that the bolt will stick to the rear so severly that you must disassemble the rifle to get the bolt loose. This problem has been recognized for a long time, and Remington had a buy-back progam for several years where you could trade the rifle and some cash in for the latest model (7400). Sadly, the program ended a couple of years ago, and the Factory now offers no remedy. There are no new receivers available. You might be able to fill the grooves by careful welding.

corvidae

Thank you for your time.