I never shoot for zero headspace. I do not want even a slight crush fit on a go gauge. I actually want the bolt handle to fall freely with a go gauge in the chamber. But I also want the bolt to stop very near the top when I put a single piece of tape on the back of the go gauge. I am thinking your rifle must have been chambered very tight to begin with.
Zero headspace is of no advantage, except maybe on a belted case and I would not even want it then. Just my opinion. If you can control the sizing of your brass you can recreate zero headspace even if you had really excessive headspace. I do minimally resize all of my ackley rounds for a slight crush fit but other wise size my brass enough to be at least .001 short of a crush fit. If you are sizing your brass acurately and not shooting factory ammo I do not see a problem with having headspace in excess of .020 over.
I ran a 223 with .018 excessive headspace for over 1K rounds without a problem. The excess headspace was created when I bushed the firing pin and realized that the bolt face was extremely out of square....then had a comedy of errors that necessitated removing more material than I liked.
I was too lazy and busy to ever get around to pulling the barrel and setting it back, so I just shot it as is, being very careful with my reloading. It was basically just a truck gun until I bought a PTG bolt to replace the one I mangled and rechamberd it to .300 whisper.
If you truely had zero headspace any wear would cause the problem. Zero minus anything equals a negative. If you had .002 headspace I do not think you would be seeing any problems. Maybe the fact that I do not run a recoil lug would explain a lack of wear on mine.
Originally Posted by duster
Thanks for your input eddybo. I am thinking that the kind of clearance you have should be considered minimum clearance in a switch-barrel rifle. Apparently mine was set to zero or very close to it, which I firmly do not believe is practical in a switch-barrel.
Of course fine gunsmiths like to set headspace as close as possible for increased accuracy,and take great pains to do so. I just do not believe this is a prudent practice in a switch-barrel.
Tight headspace in a switch-barrel ends up being a problem when FL resized cases will not fit back into the gun.