Sailormilan2 Posted January 28, 2007 Report Share Posted January 28, 2007 I am putting a 308 barrel on a Yugo M48 action. Military step barrel, with the Mauser sights. The bolt closes freely on a Forster GO gauge, but only closes about 1/2 way on a Forster NOGO guage. Just about what my normal practice is. On chambering ammo, I find that the bolt handle takes some effort to close on new, factory ammo. Not a lot of effort, but there is some resistance. So far I have tried South African surplus 7.62, Radway Green NATO spec 7.62, Lake City National Match 7.62 NATO, and Remington 150 gr. SP 308. Bolt resistance seems the same in all, and not really any harder than my reloads which I also tested. Should I leave it as is, or try to increase the chamber size a little and run the risk of going too far? Quote Link to comment Share on other sites More sharing options...
BobVZ Posted January 28, 2007 Report Share Posted January 28, 2007 The uniformity of resistance with all cartridges and the fact that you re-barreled a Yugo(safety breech) lead me to guess that the resistance you are feeling may be coming from the front of the extractor contacting the barrel face. Try removing the extractor and work the bolt and compare to working the bolt with the extractor. Then repeat, chambering a round. Note any differences. If thats not it, observe around the bolt locking lugs for any heavy burnishing caused by the bolt body rubbing against the top or bottom of the receiver cutouts when the bolt is turned into battery. I had an Argy once that did this the last few degrees of bolt rotation. I had to use a round stone to widen the receiver opening in front of the lower locking lug to free the bolt. Finally, polish a cartridge and cycle it in the chamber several times and note where the contact ring is on the case shoulder. This will give you an idea of where the contact is and what effect deepening the chamber will have. As you know, contact should be near the shoulder and not up at the neck. You might have a reamer that is a little off spec. If none of those are the culprit then we come back to your delima of whether to deepen it or not. Personally, if its as you describe, I would leave it alone but its hard to see what harm one light turn of the finish reamer would do. I guess if you feel comfortable with your "touch" then go for it. Quote Link to comment Share on other sites More sharing options...
sonic1 Posted January 28, 2007 Report Share Posted January 28, 2007 what kind on barrel is it .. Quote Link to comment Share on other sites More sharing options...
Sailormilan2 Posted January 29, 2007 Author Report Share Posted January 29, 2007 what kind on barrel is it .. It is a converted 1903 Springfield barrel off of a 1912 Steyr. Threads were cut off, rechambered to 7.62/308, reprofiled to Mauser step profile. I relieved a section on the barrel to give room for the extractor face, but apparently I didn't go deep enough. The only time I get the stiff closing is when the bolt is closing on a case. I think the extractor is being forced back against the case rim. Oh well, something to work on tomorrow. Quote Link to comment Share on other sites More sharing options...
tinkerfive Posted January 29, 2007 Report Share Posted January 29, 2007 Did ya use the same reamer as the parker hale barrel that had the tight neck? Kind of sounds like the same problem. Only difference is that this is a .308 barrel Vs the Parker Hale .305. Just thinking out loud. Tinker Quote Link to comment Share on other sites More sharing options...
Sailormilan2 Posted January 29, 2007 Author Report Share Posted January 29, 2007 I am pretty sure it is an extractor related problem. When I had the barrel off, I could see that the extractor actually extends beyond the face of the "C" ring. I had heard that some Yugos needed to have the rear of the barrel relieved for the extractors, and I guess I got one. It looks like the "C" ring is made too thin, front to rear, so there isn't enough room for the extractor, and it is worse when there is a rim under the extractor. Since the extractors does move a little. Quote Link to comment Share on other sites More sharing options...
donmarkey Posted January 30, 2007 Report Share Posted January 30, 2007 Sometimes you can thin out the extractor. But making a cut in the barrel is easier. -Don Quote Link to comment Share on other sites More sharing options...
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