Hard to close bolt shreds rim of brass

[Murderface]

Upon closing my bolt on 300 Win Mag brass, it takes considerable force to see the handle down. But after such, the bolt moves freely (easy to lift and extract). Upon opening and closing the test brass (30 times) it eventually became easier to load a piece of brass. The end result was that the rim of the case was shredded to bits, but still usable. So I took a 2nd case and chambered it and just as before, it too was hard to close the bolt with the same result. The image shows what happened when I closed the bolt.

Is it possible that the extractor is just a hair too long trying to get over the rim while closing the bolt? These are new Peterson brass I haven't gotten around to loading due to this issue. I've checked all the measurements of the brass and they are within spec as well.

 

[Supersubes]

What kind of receiver?

 

[spife7980]

What action? Could it be that the barrel counterbore isn’t wide enough to allow the extractor to slide out over the rim?

 

[KZP]

If you take out the bolt, can you manually seat a case into the bolt face by pressing it over the extractor, or does it get jammed up?

 

[Murderface]

If you take out the bolt, can you manually seat a case into the bolt face by pressing it over the extractor, or does it get jammed up?

Seating the brass on the bolt face by hand is fairly easy. Not noticeable extra resistance. But that got me thinking of doing what you just said WITH the bolt still in. So I took a new brass and seated it by hand slowly maneuvering it into the chamber. Once fully in the chamber, I was able to close the bolt with no virtually no resistance (short of freefalling) like a normal rifle. It leads me to believe that the last moment of seating before attempting to close is the problem.

 

[Murderface]

What kind of receiver?

remington 700 300 win mag

 

[KZP]

Seating the brass on the bolt face by hand is fairly easy. Not noticeable extra resistance. But that got me thinking of doing what you just said WITH the bolt still in. So I took a new brass and seated it by hand slowly maneuvering it into the chamber. Once fully in the chamber, I was able to close the bolt with no virtually no resistance (short of freefalling) like a normal rifle. It leads me to believe that the last moment of seating before attempting to close is the problem.

@spife7980 is probably correct. Can you look inside with a flashlight and see if there are gouge marks from the extractor rubbing as it expands over the case?

 

[Murderface]

@spife7980 is probably correct. Can you look inside with a flashlight and see if there are gouge marks from the extractor rubbing as it expands over the case?

I just noticed that the point of resistance is at the same point where there is a wall when trying to cam over on an empty chamber. I just checked with a flashlight and saw no gouges or obstructions.

 

[Supersubes]

If its a stock remington extractor, it’s entirely confined in the bolt face. Sometimes brass shavings pack in behind it. It should have a springy character to it. If not, blow it out as best you can.

Is this a new problem?

 

[Supersubes]

If this is a new gun and it did this from the very first round, it could just be an out of spec extractor. If it just started, it probably has debris behind it. When you push the extractor “tooth” radially outward, it needs to be able to move out of the way enough that it can clear the rim. Clearly its not doing it now. Your extractor is riveted (all magnums), and the rivet should have zero looseness to it. They do come loose now and again.

 

[sgtsmmiii]

So I took a new brass and seated it by hand slowly maneuvering it into the chamber. Once fully in the chamber, I was able to close the bolt with no virtually no resistance (short of freefalling) like a normal rifle. It leads me to believe that the last moment of seating before attempting to close is the problem.

If your resistant brass has been shot in another rifle and even re-sized - it ( they ) are probably your problem if new brass chambers easily. I'd use the new brass in the current rifle.

 

[Murderface]

If your resistant brass has been shot in another rifle and even re-sized - it ( they ) are probably your problem if new brass chambers easily. I'd use the new brass in the current rifle.

All of my brass are never-fired Peterson brass. The problem is narrowed down to the extractor having to cut its way over the rim (where all the resistance is) to fully seat the brass into the chamber as shown in the image. Now what could cause this? Well now its just a question of if the geometry of the extractor is out of spec, but I would need another extractor to compare.

 

[Murderface]

If this is a new gun and it did this from the very first round, it could just be an out of spec extractor. If it just started, it probably has debris behind it. When you push the extractor “tooth” radially outward, it needs to be able to move out of the way enough that it can clear the rim. Clearly its not doing it now. Your extractor is riveted (all magnums), and the rivet should have zero looseness to it. They do come loose now and again.

Thats where Im leaning towards (out of spec extractor) because its a newly built rifle with less than 50 rounds through it. But I dont have a riveted extractor. I have the M16-style extractor

 

[sirhrmechanic]

Has your new brass been full length resized?
New brass often comes in needing sizing. I don’t know about Peterson but certainly some are that way. Could that be causing an issue with case protruding from chamber.

Cheers

 

[Supersubes]

Thats where Im leaning towards (out of spec extractor) because its a newly built rifle with less than 50 rounds through it. But I dont have a riveted extractor. I have the M16-style extractor

That changes things. Something is inhibiting its travel.

 

[KnowNothing256]

OP, it seems there are two potential root causes, both of which have been mentioned already. Either there’s debris under the rear of the extractor, preventing it from rocking “down” to allow the extractor tip to fully rock “up” and clear the case rim, or the extractor is improperly dimensioned (either too thick at the rear, causing the same problem as the debris option, or the front, causing binding between the case rim and the inner wall of the receiver).

If you’ve removed the extractor and verified it’s clean under the rear, meaning you have a poorly dimensioned extractor, then you have a few options. Either you can contact the manufacturer and ask for a replacement, running the risk of getting sent an extractor with the same issue, you can send it to a gunsmith, or you can simply file a gentle bevel into the front portion of the outer face of the extractor, giving it more room to move towards the receiver wall and clear the case rim. I had to do this with my Howa Mini for whatever reason, and the problem went away. If you’re concerned about ruining it, ask the mfg for a new one AND file it down, they’re cheap/free and easy to swap if it’s a true pinned M16-style. Granted, I’m a tinkerer and would much rather use a file to fix my problem right then, esp on a cheap replaceable part, than wait weeks or months for a warranty claim, or pay a smith $100 to fix something I can fix myself.

And to whoever said this was because it might be pre-fired brass, hush, that’s ridiculous. Any deformation sufficient to expand the *case rim* far enough to cause extractor clearance problems would also be sufficient to make a freshly seated primer fall out, to say nothing of likely case cracking/separation.

 

[sgtsmmiii]

Think case length, not diameter, my friend.

 

[KnowNothing256]

Don’t see how that scans either, the rim would still fit. Unless you’re asserting that the receiver interior wall tapers to a smaller diameter further to the rear (it doesn’t), so that a too-long case would move the moment where the extractor skips over the rim into a too-tight spot further to the rear. That’s not plausible, for multiple reasons.

I think you might be suggesting that a too-hard bolt close can be caused by excessive headspace, which it absolutely can, but that has nothing to do with the cutting of the case rim by the extractor that OP is observing.

 

[supercorndogs]

Mag bolt face Remington extractors are riveted, that makes it pretty tough to remove for inspection. Its not nessasry to remove to test or clean behind though. To test it you simply push the claw into the recess for it in the bolt face. If it goes in its good, if it doesn't something is wrong. The next step if it doesn't go in all the way is to figure out why. Usually its obstruction behind it, but there have been some cases where the recess was not deep enough to allow the extractor to move all the way, out of the way.

 

[spife7980]

Mag bolt face Remington extractors are riveted, that makes it pretty tough to remove for inspection. Its not nessasry to remove to test or clean behind though. To test it you simply push the claw into the recess for it in the bolt face. If it goes in its good, if it doesn't something is wrong. The next step if it doesn't go in all the way is to figure out why. Usually its obstruction behind it, but there have been some cases where the recess was not deep enough to allow the extractor to move all the way, out of the way.

It’s been converted to m16 extractor

Thats where Im leaning towards (out of spec extractor) because its a newly built rifle with less than 50 rounds through it. But I dont have a riveted extractor. I have the M16-style extractor

 

[supercorndogs]

It’s been converted to m16 extractor

I see in the thread where it says that now. I am surprised the cut in the rim of the case is not about 2x as wide if its an M16 extractor. But that brings us full circle back to counterbore and bolt nose clearance.

 

[Murderface]

I see in the thread where it says that now. I am surprised the cut in the rim of the case is not about 2x as wide if its an M16 extractor. But that brings us full circle back to counterbore and bolt nose clearance.

I fixed it just now. The hook end of the extractor tooth was just a bit too long . I took a file to it and when I checked to see if it will close, I nearly all resistance I originally had. Before, I hand to use arm strength. Now, its just a flick of the wrist. The resistance is above that of running the bolt on an empty chamber. Apparently (but reasonably) with these M16 extractors in bolt guns, some gunsmiths arent checking for this problem.

 

[PCR]

Didn’t read the whole thread and I saw your fix but it sounds like your counterbore isn’t wide enough for an m16 style extractor. If you had an m16 extractor upgrade and the smith didn’t widen your counterbore cut it could interfere