I had my M1A up at the Red Bluff shoot a couple weeks ago, and on the last 4 shots of the Sunday PM redcoat, it started short stroking. OK, so I've been a little lazy on cleaning up the gas system...
So I start to take it down, and hey - what's this hole here where shouldn't be a hole?
Looks like the spindle valve pin must have worked its way loose, and the next shot probably popped the thing right out, if the spring didn't do it on its own. There was no one to my side to 'intercept' it, so it's probably still in the mud out there.
Not that it's an expensive part, but that's just annoying... !@#)
That's a new one for me .
I recall the only maintainance required was to push it in and turn a few times .
One problem I experianced was a broken trigger pin , yup gun fired when I removed the mag .
Fortunately , the muzzle was pointed at the berm .
I haven't experienced that one yet, but this last spring I tore down my M1A for cleaning after a day of shooting to discover the bolt roller had mysteriously vanished. The funny part is that the last 40 or so rounds of the day had grouped much tighter than I'd ever gotten out of that rifle before. A closer investigation after replacing the roller revealed a clearance issue at the top of the rear receiver cutout - the roller could, and apparently was, contacting the receiver cutout at the rear of the bolt travel just enough to affect accuracy. Something I never would've discovered otherwise.