Bolt Scraping Inside Of Body

[alpha_q_up23]

So I was playing with one of my mags this past weekend and I came across an issue where it wouldn't fire, ultimately i figured out it was a problem with the lv 10 bolt/sear.
When I disassembled my mag I noticed the bolt had been scraping the inside of the ULE and "chipping away" at the inside of the ULE, today I got one of my pump mags with a Gearheads Helios body on it and found out it had the same scraping/marking but not as severe.
I changed my bolts and sears on both and it seemed to fix the issue(s) I was having, just curious if anyone else had this issue and what can you do to prevent this issue, as Ii have a few high end bodies I'd prefer this not happening to.
I suppose the general answer of "check your bolt and sear constantly" works , but any other advice?
Also when I tighten my fieldstrip screw I only keep it finger tight, if that's any useful information.

[caylegeorge]

I had this problem in my RPG modified ULE body - where it would scrape the topside of the body and get bolt stick/ wouldn't fire. I could fix it every time by loosening the field strip screw a little, but I never kept it very tight to begin with.

I was wondering if perhaps the rail had lost too much material in polish/ano that when fully tightened the valve was no longer pointing straight down the body. If so could that be fixed with a very very thin shim between the rail and valve? Even something like a layer or two of tape?

[tucson.az.jbreen]

Idk if my info is relevant, but my classic valve likes the field strip only snug, like the rubber urethane washer makes contact and then like an eighth of a turn more.

My x valve likes the field strip screw about as tight as I can possibly get it with my fingers.

The valve and body don't seem to align well unless I really tighten it down on the x valve.

I have read on this forum that some people have to tighten their x valve with a wrench, but that scared me and I wouldn't do it. Not with as many helicoiled valves floating around.

Jim

[Menace_AO]

Most of the classic bodies I've seen have this, and it's one of the few things about mags that really bugs me.

Cannot abide metal-on-metal wear in the sense of chewing.

As some have indicated, I think it is a matter of parts alignment. There are numerous factors at play here.

As for tightening the field strip screw, you might try either cranking it down with super-finger pressure, or else the small end of a wrench, and seeing if that doesn't do it.

There is a substantial amount of slop in the body/valve fit, and the tighter the screw, the further from the top.

I have wrapped thick packing tape (carefully and evenly) around the smaller OD of the valve to improve concentricity in the body (using a razor blade to trim around the needed areas).

Never had an issue after that, but it's hard to say if your mileage will be the same.