T
TRA
Guest
How much is the rim expanding when fired?
B
Bluefield
Guest
It is not the rim that is expanding. The bolt face recess is not aligned with the chamber so the rim jams in the recess.
Mike Bryant
Active member
I'd go slow on opening up the bolt face, going .005" at a time. Sometimes going to too much clearance on a case head will cause problems with ejection at least on smaller cases. But, a little excess clearance on the bolt head shouldn't cause any problems with ejection as it's a large case. Sounds like you figured out what the problem was with the extraction issue.
B
Bluefield
Guest
Thank you all for your help with this odd and perplexing problem.
4
4Mesh
Guest
If you guys would humor me just cause I'm not real sharp at this stuff. Now, I've seen some Winny's's but I'm not overly familiar with them.
So what you're saying is:
( ( The chamber is eccentric to the threads on the barrel, OR the receiver threads are eccentric to the receiver bore, ) AND the bolt face is eccentric to the bolt body. ) AND the case expands so much AND the eccentricity is so great that it causes a stuck bolt situation immediately evident upon touching the bolt?
I ain't buy'n it.
Ok, over pressure. Fine. Lugs dug into the receiver, perhaps. But even if all your situations are correct, it still tells me the gun is way over pressure. To the point of being a concern.
Furthermore, if the thing is eccentric by an amount to cause what is being suggested above, that bolt handle will NEVER open it. You should be able to roll the case on a table and see the amounts talked about here. I'd be more willing to believe the extractor was digging into the side of the rim due to a sharp edge, or it rolling in it's slot, or whatever.
So what you're saying is:
( ( The chamber is eccentric to the threads on the barrel, OR the receiver threads are eccentric to the receiver bore, ) AND the bolt face is eccentric to the bolt body. ) AND the case expands so much AND the eccentricity is so great that it causes a stuck bolt situation immediately evident upon touching the bolt?
I ain't buy'n it.
Ok, over pressure. Fine. Lugs dug into the receiver, perhaps. But even if all your situations are correct, it still tells me the gun is way over pressure. To the point of being a concern.
Furthermore, if the thing is eccentric by an amount to cause what is being suggested above, that bolt handle will NEVER open it. You should be able to roll the case on a table and see the amounts talked about here. I'd be more willing to believe the extractor was digging into the side of the rim due to a sharp edge, or it rolling in it's slot, or whatever.
OK, here's where I've seen it.....factory chambers/guns and full-on customs using my fat-butted chambers.
In the case of the factory chambers, #1 the chambers were "wallowed" out such that they were oversized by 10-12thou over new cases. This isn't all that uncommon. Combine the misalignments present in a factory rifle coupled with the misalignment generated by the cases blowing out ON ONE SIDE as they do and you've got a situation where depending on how the case is oriented they will sometimes rub inside the bf recess upon firing. No over-pressure, just normal expansion.
In my custom actions I'm playing with chambers from .005 to .009 over new cases. I'm settling on about .007 as a good compromise between clicking and alignment because on two of my .009 oversized ones I find that on the eccentric cases I sometimes can't get them to chamber because the butt's moved over so far it can't find the hole in the boltface!
All's I'm saying is that I've had several situations where the extractor ring of the case is actually rubbing inside the boltface recess. And those old M70's weren't known for concentricity.
AND, I don't buy into the lug setback theory
pthlpthththlplplpp and it seems to me that lubing the lugs should at least change the feel if this were the deal.
Sounds like the DIQ is perty perceptive and he'll soon enlighten us all as to the real problem...
al
In the case of the factory chambers, #1 the chambers were "wallowed" out such that they were oversized by 10-12thou over new cases. This isn't all that uncommon. Combine the misalignments present in a factory rifle coupled with the misalignment generated by the cases blowing out ON ONE SIDE as they do and you've got a situation where depending on how the case is oriented they will sometimes rub inside the bf recess upon firing. No over-pressure, just normal expansion.
In my custom actions I'm playing with chambers from .005 to .009 over new cases. I'm settling on about .007 as a good compromise between clicking and alignment because on two of my .009 oversized ones I find that on the eccentric cases I sometimes can't get them to chamber because the butt's moved over so far it can't find the hole in the boltface!
All's I'm saying is that I've had several situations where the extractor ring of the case is actually rubbing inside the boltface recess. And those old M70's weren't known for concentricity.
AND, I don't buy into the lug setback theory
pthlpthththlplplpp and it seems to me that lubing the lugs should at least change the feel if this were the deal.Sounds like the DIQ is perty perceptive and he'll soon enlighten us all as to the real problem...
al
4
4Mesh
Guest
But Al, he said 3 different brands of ammo (so I assumed new ammo). This being the first firing, it seems hard to believe it could be this bad. And, if it is, certainly as I said above, he should be able to roll one of these on a table and it should look like a weeble-wooble. At that rate, I'm not sure it will roll. More like bounce.
No matter what the shapes, the bolt should BEGIN to open, then tighten if there is a shape issue after firing. Otherwise, if the cartridge is tight before you move the bolt, it's over pressure. Imo... This case should be so bananna'd he should be able to see this with the naked eye.
No matter what the shapes, the bolt should BEGIN to open, then tighten if there is a shape issue after firing. Otherwise, if the cartridge is tight before you move the bolt, it's over pressure. Imo... This case should be so bananna'd he should be able to see this with the naked eye.
B
Bluefield
Guest
Final chapter
I set the bolt up in the lathe and opened up the bolt nose recess .010 thou. Took the gun to the range and fired two rounds. All is normal. Cases are round and not banana'd. You learn something new every day.
How did it ever leave the factory like this and why was it never discovered or corrected all these years? Maybe someone swapped bolts or lost the bolt and replaced it with another.
I set the bolt up in the lathe and opened up the bolt nose recess .010 thou. Took the gun to the range and fired two rounds. All is normal. Cases are round and not banana'd. You learn something new every day.
How did it ever leave the factory like this and why was it never discovered or corrected all these years? Maybe someone swapped bolts or lost the bolt and replaced it with another.
G
gunsmither
Guest
How did it leave the factory? Indeed! I couldn't begin to count all the factory guns that I've repaired that came screwed up right from the get go. Quality control seems to be an afterthought with many gun manufacturers.