Too Tight Headspace?

[JAMES KING]

I recently bought a arsenal refurbished Mosin Nagant 91/30 made in 1931. The bore and chamber look new after a thorough cleaning with solvents brushes etc.

It will chamber and extract a round, but only by banging the bolt closed with the heel of my hand.

I have tried the following: another bolt head and using the bolts from two different rifles without any different result. (The bolt from this rifle works flawlessly in the other two rifles)

I have peered up the spout and can detect no burrs or irregularities or dirt. etc. I am satisfied it is completely clean.

I have reluctantly concluded that it was made with the head space a smidge too tight.

Somebody suggested very light chamber reaming. Since the cartridge head spaces on the rim I am not clear on how this would help.

It seems obvious that since the thing will close & extract but with difficulty, it can't be more than a couple thousanths off.

I noticed that when I got the rifle I had to really bang away to get the bolt turned from the closed position. I have since wondered if this could have caused some kind of damage or deformation that I cannot see. ????

Does anybody have a suggestion?-------------Thanks

[flounderman]

is it shinning the head of the case after you close the bolt on it a few times. if it is headspace, the bolt face should mark the head of the case very visably. if the head doesn't show the bolt is rubbing it hard, check to see if the bolt handle has clearance, or maybe the extractor slot isn't indexed properly and the extractor is hitting. if it is the shoulder that is hitting you could take a little off the base of a full length die. first place to look is to see if the bolt face is marking the case base.

[Hip's Ax]

James, do you have more than one kind of ammo to try? I would imagine the rim thickness of various ammo made in various countries might wander a bit. What ammo did you use when you found the bolt to be difficult?

[dragonrider]

Aquire a go gage and go from there, if it won't close on a go gage then your assumsion could be correct. If it does close on the go gage then the thick rims could be the answer.

"Somebody suggested very light chamber reaming. Since the cartridge head spaces on the rim I am not clear on how this would help."

A chamber reamer will cut the rim face also.

AND welcome to the forum, you won't find a better place for your questions than here.

[JAMES KING]

In reply:

I am using clean surplus Russian Army light ball rounds. It was made for this stuff.

I am only cycling rounds and have made no attempt to shoot it yet.

Since the cases show no bolt head deformation It appears not to be a headspace problem.

BUT. the extractors of every bolt head I have tried are beating up the cartridge rim edges so I guess It is related to the extractors not being able to easily ride over the edge of the rims. In fact, when I put on the extra bolt head and forced the bolt closed by banging it with the heel of my hand, there was a very small sliver of the rim removed and a small sharp burr left on the rim.

Since I am having similar trouble with the other bolts I am still very puzzled as to the cause and what to do about it. I haven't tried a brand new extractor, but really can't see why that would do any good.

If it is an extractor problem and there is nothing wrong with the extractors, what could be wrong with the rifle that causes the extractors to not work properly and is it fixable do you suppose (or I am I flogging a nice-looking dead horse?

All the bolts including this one work like a charm in the other guns. I hate to give up on this one because it is so pretty.

[flounderman]

blacken the extractor all over and close it over a case. see if any rubs off. remove the extractor and close the bolt over a case and see if that solves the problem. if the bolts work in other rifles, and the bolt works without the extractor in, the extractor is hitting the end of the barrel. a little of the tip could solve the problem if that is the problem

[Casting Timmy]

Are you loading the round out of the magazine? Or are you just dropping the round in front of the bolt and pushing the bolt closed?

I'm probably wrong, but I really think this rifle likes to load out of the magazine.

[JMtoolman]

Another thing to look for is the extractor machined area on the outside of the chamber. Sometimes these areas are full of dried grease and ****. It's a hard area to clean, but a dental pick and q-tips with solvent will work. The toolman

[akajun]

This is a common problem. I have gone through many mosins, and a few have had "sticky bolt". Usually it is caused by a build up of laquer in the chamber, and is only noticed when shooting brass cased ammo. You can always fire steel cased ammo and you will not notice it.
However I did have one rifle where there was a burr in the chamber which I was luckily able to polish out. Look for a shiney spot on the brass body it should tell you where it is.Heres what I did. I took 2 brass cases and fired them, save one. I then drilled out the primer and taped the hole for a allen head bolt on the other one. I then coated the case with 600 grit lapping compound and turn it with a long t handle allen wrench. after a few turns re apply the compound and go at it again. After two or three treatments clean the snot out of your chamber and attempt to drop the fired case you saved into the chamber. When you can see a marked difference, stop and go fire the gun to see if you went enough.

[mroliver77]

I cannot remember for sure how the Mosin is set up but most rifles have a relief cut in the barrel face for the extractor to fit into while grabbing the rim. If slot is filled with crud or not in the correct place the extractor can hit and be a bear. The fact that you had to beat the bolt to open it originally is a sign that something is amiss. Try blackening the bolt and extractor with candle soot and see what rubs off. If you can remove extractor do it and see if it still sticks without it. Make up your mind that you can figure this out. Take your time, examine, think, understand how it all works. You will figure it out!
J

[leftiye]

Could be bullet stuck into rifling, or chamber neck too short (pinching front of neck of ctg.), or neck of chamber too tight, extractor against barrel or gunk as mentioned, or too short headspacing, or too tight chamber in body of ctg. area, or maybe burrs on the chamber, or...

[nicholst55]

I'll bet it's something related to your extractor. A guy on the FAL Files forum had a Mosin that exhibited similar problems some time ago. He exhausted every idea that anyone could think of with no luck, and he refused to give in when it was suggested that he part out the gun and buy another for $79.

He eventually determined that the extractor was very slightly bent; a new extractor cured his problem entirely. It would probably have to be multiple extractors in your case, since you've tried different bolt heads. Perhaps the extractor groove is misaligned or too narrow?