What did you do to fix them? Reason I ask is I have a new Ruger American 17HMR that gets around 2 fail to fires out of 10 shots with 2 different brands of ammo. A non fired round will not extract as it hasn’t jumped back into the extractor leaving me to think the headspace is too large.
I’ve sent it back to Gravel Agencies for them to sort out as it’s not worth keeping if it’s not reliable.
Bush1, for the zippers I 'polished' them with 200g then 600g w/d paper. Only spent about 15 minutes or less on either one, the first (ruger .223 Standard) I hit with 200g for 50min on an osc-sander HA!. I've seen some people say they sat watching TV while cycling the bolt interminably. I don't have that patience or that time to kill, so I went with the s-paper. I also checked inside the recvr to remove any 'rough spots' tho they weren't too bad. Now both bolts will 'fall thru' if I tip the muzzle down and they're QUIET. And I only lube the lugs.