I dry fired several times and it seems to be working, but really don’t know what “sounds right” should sound like. I don’t have enough experience. I haven’t cleaned the trigger. I have a new trigger for a spare, so I’ll put it in and see what happens. I’m going to change the spring too, I guess that wouldn’t hurt.
Cool! Check the slot the cocking piece slides in, in the receiver to make sure there's nothing going on there too. Have you changed anything, like stocks or anything that might coincide closely to when the issue appeared? Since you're gonna change springs anyway, which is never a bad idea, put the bolt back together with no spring and shake it back and forth. It should move to and fro freely with no spring.
There is some grease in the slot, but that is it. This is a new build, everything is original.
Ahh. I'd look for bedding where it shouldn't be. Is it a glue in?
It isn’t a glue in. What should I be looking for with the bedding?
Yes, it should, as long as it's getting full travel. That .048 MIGHT imply there's something still stuck in there that cleaning just hasn't gotten but I'm assuming the bolt is clean. I'm saying that because a tiny brass disc from a primer could potentially get wedged somewhere pretty tight but you said you looked in there with a borescope. So I'm going with the bolt is clean! The math is pretty close to that scenario though. So like I said, double check the simple stuff if you're not 100% sure it's clean in there. No choice but to assume those things on the internet so we'll go with that. But you're no dummy and you're going about this seemingly very well. I'm surprised you haven't found it already.
Anything that might impede trigger or firing pin travel/function. You might've said already but what action are you working with?
It won't by much but brass can and does compress a little with fp strike. Now if it was un fireformed 220 in a ppc or similar, it can move a fair amount because the neck shoulder junction is the only small patch holding it against the bolt face.
But this is a 308, so im with you, it has to be in the ignition.
Yes, I would think so. Over annealed brass...maybe could do it??? But not .048. I keep coming back to that because the primer on the far left had NO hit that was apparent. Still sounds like something in the bolt but I'm going with the assumption it's CLEAN.
Well I dropped the firing pin during disassembly and tip of firing pin is bent slightly causing friction with firing pin hole. I’ll try to straighten it out, but likely will need new firing pin.
Hmmm. That may well be the whole issue but it shouldn't travel freely with no spring if the bend is binding it up...unless I'm not thinking of something here. Now, what caused that. You're not the first person to have a bent pin in recent posts on here. Maybe a bad batch? IDK.
I was able to straighten the pin that I dropped and bent. It was bent about 3/4” from the tip, so I could straighten it out pretty easy. Once I straightened out the pin, I assembled the bolt without the spring and sure enough there was quite a bit of drag in the last 1/8” of travel. I coated the end of the pin with sharpie and cycled it and found two high spots. I polished the pin some then lapped the pin in the firing pin hole using JB bore paste. That did the trick. The firing pin now shakes freely too and fro, really smoothly. I’m pretty sure that will solve the problem.
