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Discussion Starter · #1 ·
A friend asked me to look at his Winchester M100 (308 W) for failure to extract. The problem surfaced several years ago but his life circumstances at the time prevented him from any evaluation. Likewise, he has limited recall of the situation when the problem arose.
I fired a round and it did not extract. Ramrod removal produced a fired brass with the expected rim damage from the extractor running through the rim (so, at least there is an extractor). Further inspection of the case (see image)
Cylinder Bullet Gun accessory Ammunition Wind instrument


shows a ring around the neck. I measure the neck at 0.350" on either side of the ring; and 0.352" over the ring. Web diameter is normal (0.469") and the primer seems normal, without pressure signs. A thumbnail definitely catches on the ring.
I bore sighted the chamber and there is a circumferential groove in the neck area of the chamber, corresponding to the ring. Incidentally, the state of the bore is rather poor.
So, my first question is: What could have happened?
Second question: Is there a fix? Could you ream the neck from the body to the groove, thereby removing the locking groove? This would only leave a short length of neck to align the bullet with the bore.
Given the poor rifling and a well-used rifle, not famous for being accurate, is any remedy worthwhile?
Thanks for your interest. I am eager to read your thoughts.
 
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Sounds like a steel chip got caught/wedged when the chamber was cut and the finish reamer didn't take it out.
Which it probably wouldn't have.
I don't know if anything can be done myself.
A experienced gunsmith would have to look at it and judge the tolerances. But IMHO it doesn't look promising.
I've seen worse in person. Maybe 30 years ago or so one of the first Auto Ordnance 1911's I saw had a ringed bore from something like that and shouldn't have left the factory.

Really, that should have shown up in test firing.

Another thought.
If this wasn't a problem from the get go it's possible during cleaning that a defective chamber brush or improvised one with a steel core did the damage but I don't know if it's possible.
 

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Hmm, that is peculiar.
I cannot imagine what would have caused that sort of defect in the throat of a rifle that must have worked correctly for a very long time if the bore is actually somewhat degraded also. From my experiences it takes a lot of ammo to degrade a bore. I wonder if you might find a better barrel from someplace and have it replaced at a reasonable price?
 

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What concern me is the reasonable price.

I know with Winchester either changing hands or production point over the decades it might be a shot in the dark(no pun intended) but they may at least have some spare barrels on hand. Although more likely any would be long gone it wouldn't hurt to ask.

There's NUMRICH and there's also a place here in NWA called The Gun Garage for some parts I don't have their card... though I did ah here they are

 

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Discussion Starter · #8 ·
I've looked for a bbl at Numrich, Jack First and Bob up in Rogers. None available. Thanks for the leads on the other parts dealers.
I doubt if the owner will be interested in sinking too much money in this gun. He has newer, better arms. This is a "first gun" kind of sentimental thing.
 

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That’s just plain strange. I’m having trouble coming up with a plausible explanation for a rifle suddenly developing that issue.

I don’t have enough experience to say for sure, but I have to think the only options are rechambering, rebarreling, or walking away. I’d just walk away; sell it as-is and never look back.

That’s a strange one.
 

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I'll admit right from the get go I'm just spit ballin' here. But is it possible the length of the case is too long and the neck upon being chambered it ending up right where the rifling begins and it's getting stuck after firing abd being expanded and that's possibly why it's not extracting? I'd start by using the straight or curved (which ever would work best) Hornady OAL gauge with their .308 modified case and get the OAL of the chamber. Then you can compare that to the ammunition being used. If that's fine then it's going to be a process of elimination.

But now that it jsut came to me, the very first thing I'd do is find one of those As Seen On TV Lizard Cams. They work pretty damn good for a poor mans bore scope. I bought one for something else and thought I'd try it for a borescope and I was shocked to find it worked. You are limited on caliber you can put it in, but it will work in a .308. Maybe do that and see what you can see? Then do the above next. And again, if neither of those give any answers continue with the process of elimination to find the culprit.

One last thing. out of curiosity, is the ammunition being used .308 or is it possibly 7.62X51? Reloads or factory loads? Good luck!
 

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Discussion Starter · #12 ·
GlockMeister, I have a borescope. There is a ring circumferentially in the neck area of the chamber. With a probe, I can feel the probe catch in the groove. The brass from the neck is forced into the groove, making a 0.002" retainer!
I don't know what made the groove. For years the rifle shot and ejected empties without problems.
Is there a way to fix it?
What would happen if a gunsmith opened the chamber to the same diameter as the groove, but left the rest of the neck at specification diameter?
 
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if it's only .002 the neck could be reamed or polished enough to clean it up.
 
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Discussion Starter · #14 ·
if it's only .002 the neck could be reamed or polished enough to clean it up.
I am tempted, of course with the gun owner's approval, to make a wooden dowel pilot of bore diameter and attach emery cloth to touch just the neck chamber from beginning of neck to the groove. Spin this with an electric drill. If the gun owner agrees he has no useful firearm, he may want to try something like that. If he is willing to spend some money, I'd suggest he take it to a well-credentialed gunsmith!
 

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chamber necks have a taper to them.
you might be able to polish it out, but you'll have to be very, very careful.

emery cloth will cut pretty quickly.
maybe do a slug and use that as a lap with some compound, 20-30 seconds will probably take enough out.
it's one of those situations where good will trump perfect.
 

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Discussion Starter · #16 ·
MORE DATA
I spoke with the owner of the gun. Details are sparse, but he recalls that his father shot a 30-30 round in this 308 chamber. They had to hammer the action open. He can't remember if the gun ejected properly subsequent to this event. The fact that it has been in a gun cabinet for nearly twenty years suggests the problem was present immediately. It does chamber and fire a 308 round, just won't extract as per the initial post.
So, I loaded an empty 30-30 in the magazine, but the rim catches and the bolt can't lift it from the magazine. Next I laid an empty on the magazine follower with the neck just aligned with the chamber, and the bolt closed and locked. The firing pin released with a trigger pull. The bolt came rearward with moderate resistance and the case stayed in the chamber - ramrod removed. The case mouth was reduced in diameter, indicating the case neck must have been forced into the leade. Aligning this case with one of the previously shot 308s (see photo. L->R, ripped rim, fired 308, 30-30, 308 fired in this rifle. Front face of the rims are aligned.) tells the story. The 30-30 case mouth was crammed into the leade, when the cartridge was fired the pressure must have been tremendous! I suspect when the brass-skirted bullet finally moved, the groove in the chamber was made by gas cutting.
I think the solution will be to lap the chamber to eliminate the groove.
Thanks, All, for your help.
Tin Cylinder Gun accessory Composite material Gas
 

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MORE DATA
I spoke with the owner of the gun. Details are sparse, but he recalls that his father shot a 30-30 round in this 308 chamber. They had to hammer the action open. He can't remember if the gun ejected properly subsequent to this event. The fact that it has been in a gun cabinet for nearly twenty years suggests the problem was present immediately. It does chamber and fire a 308 round, just won't extract as per the initial post.
So, I loaded an empty 30-30 in the magazine, but the rim catches and the bolt can't lift it from the magazine. Next I laid an empty on the magazine follower with the neck just aligned with the chamber, and the bolt closed and locked. The firing pin released with a trigger pull. The bolt came rearward with moderate resistance and the case stayed in the chamber - ramrod removed. The case mouth was reduced in diameter, indicating the case neck must have been forced into the leade. Aligning this case with one of the previously shot 308s (see photo. L->R, ripped rim, fired 308, 30-30, 308 fired in this rifle. Front face of the rims are aligned.) tells the story. The 30-30 case mouth was crammed into the leade, when the cartridge was fired the pressure must have been tremendous! I suspect when the brass-skirted bullet finally moved, the groove in the chamber was made by gas cutting.
I think the solution will be to lap the chamber to eliminate the groove.
Thanks, All, for your help. View attachment 170404
Wow, if that all did happen and it's been subjected to almost catastrophically high pressures as a result, I wouldn't want to be in the immediate vicinity when/if it gets fired again.
 

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Discussion Starter · #18 ·
I need a face-palm emoji. This weekend, I was telling one of my sons about the "ring neck" and my plans to enlarge the chamber. He suggested that I could simply shorten some 308 cases so the case mouth was even with the groove!
So, I shortened some once-fired .308 cases to 1.905 inches, which put the case mouth at the bulge on a fired case. I loaded three using a mid-range charge and voilà, it worked like a charm.
Of course, now I will have to handload for my friend forever...or teach him to reload.
 
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