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Posted: 10/4/2007 11:29:32 PM EDT
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Have you guys ever seen a lower do this to buffers? Link due to huge pic The outer edge is completely worn down to the aluminum under neath and there are a pair of tracks from the notch in the bolt carrier caused by closing the upper to the lower. This is only with about 5k rounds through it and alot of the damage came from shooting not opening and closing the rifles halves... I'm wondering if this is fixable by me or does it need to go back to bushmaster. I want to SBR the lower, but not if it's doing this to buffers. ETA: for history: When it started to develop the perpindicular stripes I saw it and used a file to lightly round the trailing end of the bolt carrier so it didn't scrape with a sharp 90degree angle. This helped a little, but apparently hasn't stopped the progression (it also removed finish, but that is for a later time to fix). The rear of the carrier is smooth, has normal rounded edges, and shows no burrs that could also add to this. I had not tried replacing the buffer, but aside from the face wear the rest of it looks fine so I'm a little reluctant to think it's a faulty buffer itself... |
 1. The buffer retainer hole was drilled too far back in the receiver, and when the upper is closed/locked home, the back of the carrier is not pushing the buffer back away from the pin. The dents here are the buffer slamming into the buffer retaining pin, which again, should not happen since the only time that the buffer should touch the retaining pin is when the upper is open. 2. These ridges are being caused by burs in the back of the carrier on the outer and inner rim surface (most likely a bur on the bottom C cut for buffer retainer clearance. 3. Some small scrap marks are normal, but since the carrier in this case has a nasty bur at the carrier bottom C cut out, it was digging into the face of the buffer every time the upper was opened and closed. Also to point out, the buffer is question was a cheap unit which was not correctly hard anodized. |
| my bushmaster did the same thing #1 that is. also canted fsb. had to run my rear sight all the way to the left. It was my first ar, and my last bushmaster. I sold it at a big loss(told the guy that bought it what was wrong with it) After a lot of research on Ar15.com, I bought a CMMG 16"mid. great rifle with 0 problems. Have since bought a colt 20" A2 also 0 problems moral of this story? Buy quality the first time. |
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