WayneinMaine
Inactive
Many of you may remember my posts regarding the 3 1917 Enfields with which I've been playing. A gunsmith said #2 had dangerously excessive headspace and started racking up the expenses. I got the sense he was incompetent and brought the gun home (250 miles one way). I bought a Forster field gauge and the bolt would not close on it, with the barrel screwed in hand tight. He has refused a refund saying that I must have swapped bolts or something, or that the rifle somehow fixed itself. I actually have that in writing.
Anyway I bought #3 while I was dropping #2 off. Rested, at 25 yards, it shot a 6-inch group while marching steadily back through the stock. It would not pass a field gauge but I had 3 partial case-head separations out of 8 rounds. I used reloads previously fired in #1, which has more headspace than either #2 or #3 (#1 almost closes on the field gauge yet is accurate and I get multiple reloads per case) The cases were super thin but separation wasn't obvious until I was inspecting the cases for reloading. The cases seem to be separating in exactly the same place, on one side of the case only, and one of the bolt lugs has pitting that I initially mistook for grinding marks, and I doubt it's contacting the receiver.
Now the question: I'm planning on re-barreling in .308 with a short chambered drop-in from Criterion barrels. I just picked up a lathe and was thinking of blueprinting the action. and turning down the back of the bolt lugs on the lathe a bit to true them up. I'd like to retain the old .30-06 barrel but don't have any experience threading, especially with square threads. To keep the "timing", would there be an problem with turning the shoulder back the distance of one thread and down to minor thread diameter, so a small portion of the shank nearest the shoulder has no threads at all? Then I could re-chamber and would maybe have to reface the chamber area and extractor groove. I'll probably get a spare bolt body just in case, or I'll test it with one of my other bolts if it headspaces ok.
Anyway I bought #3 while I was dropping #2 off. Rested, at 25 yards, it shot a 6-inch group while marching steadily back through the stock. It would not pass a field gauge but I had 3 partial case-head separations out of 8 rounds. I used reloads previously fired in #1, which has more headspace than either #2 or #3 (#1 almost closes on the field gauge yet is accurate and I get multiple reloads per case) The cases were super thin but separation wasn't obvious until I was inspecting the cases for reloading. The cases seem to be separating in exactly the same place, on one side of the case only, and one of the bolt lugs has pitting that I initially mistook for grinding marks, and I doubt it's contacting the receiver.
Now the question: I'm planning on re-barreling in .308 with a short chambered drop-in from Criterion barrels. I just picked up a lathe and was thinking of blueprinting the action. and turning down the back of the bolt lugs on the lathe a bit to true them up. I'd like to retain the old .30-06 barrel but don't have any experience threading, especially with square threads. To keep the "timing", would there be an problem with turning the shoulder back the distance of one thread and down to minor thread diameter, so a small portion of the shank nearest the shoulder has no threads at all? Then I could re-chamber and would maybe have to reface the chamber area and extractor groove. I'll probably get a spare bolt body just in case, or I'll test it with one of my other bolts if it headspaces ok.