Bolt on my mosin is tight.

[theneckie]

Took my mosin out today and put a few rounds through and it cycles fine until the last round is fired, and then I need to basically beat the bolt lever open. Any ideas?

 

[j8064]

Took my mosin out today and put a few rounds through and it cycles fine until the last round is fired, and then I need to basically beat the bolt lever open. Any ideas?

It's the nature of the beast. Clean the bejesus out of the cosmo on the bolt and in the chamber. And always have a rubber mallet handy at the range.

 

[coopermania]

Post a pic of the last empty case you fire, Sounds like high pressure. Was this ammo reloads ? New boxer primed or import corrosive.

 

[coopermania]

It's the nature of the beast. Clean the bejesus out of the cosmo on the bolt and in the chamber. And always have a rubber mallet handy at the range.

I hope your not serious about bring a rubber mallet with a rifle to the range. Anytime you have to beat open a action on a firearm you need to cease firing and find out what the problem is.

 

[clandestine]

Most Mosins with "Sticky Bolt Syndrome" can be improved. Installing a Sniper Bolt Body or longer Bolt Handle Helps (Creates more leverage).

Some tension comes from old Cosmoline in the Bolt Assembly (Tear it down and CLEAN it well)

Some tension comes from BAD Headspace (This may require a Gunsmith)

Some tension comes from rough Locking Lugs (You cant lap the lugs in without opening up the headspace)

Some tension comes from a rough chamber (If not pitted it can be polished out)

Some tension comes from rough machining on the Bolt Body and Cocking Piece (It can be cleaned up)

Some tension come comes from a tight Bolt Face recess, bolt or rough Bolt Face 9A lathe is needed to clean that up)

Some tension comes from TOO MUCH Extractor tension or sharp edges (This can be tuned and contoured)

 

[lee2]

heres a good article to read.
http://www.russian-mosin-nagant.com/sticky_bolt.htm

 

[j8064]

I hope your not serious about bring a rubber mallet with a rifle to the range. Anytime you have to beat open a action on a firearm you need to cease firing and find out what the problem is.

It's a long standing and common joke about Mosin bolts. Evidently you've not fired one with milsurp ammo.

Clandestine chimed in as I knew he would.

 

[md_rick_o]

It was the russian work out for right arms.

 

[coopermania]

It's a long standing and common joke about Mosin bolts. Evidently you've not fired one with milslurp ammo.

Clandestine chimed in as I knew he would.

I own 2 Mosins as a matter of fact, I bought a 91/30 from a store down on the waterfront of old town Alexandria way back in the 70s and I have a 44 that my dad brought back from Viet Nam . I myself have never been a Mosin fan but my kid is and he has shot tins upon tins of import corrosive and never had a hard bolt to open. Maybe you need to take yours to chad and have them checked.

 

[theneckie]

Yeah I believe it's import corrosive just generic white box ammo and it's only on the last shot, also did it when loading a singe round. Other that that it was a fun shoot.

 

[j8064]

I own 2 Mosins as a matter of fact, I bought a 91/30 from a store down on the waterfront of old town Alexandria way back in the 70s and I have a 44 that my dad brought back from Viet Nam . I myself have never been a Mosin fan but my kid is and he has shot tins upon tins of import corrosive and never had a hard bolt to open. Maybe you need to take yours to chad and have them checked.

Whoa, apparently someone got their fuse lit. OK. You've shot a Mosin.

Chad is a friend of mine and has checked many of my restorations. My remark about mallets and Mosins is a well known "funny". Get over it.

Moving right along.

 

[Threeband]

... And always have a rubber mallet handy at the range.

Rubber mallet is to be shattering and breaking in temperature of minus 30 or 40 Celsius of Springtime in Beautiful Rodina.

In Glorious Red Army is special non-shattering mallet issued especial for the opening of the bolt of Glorious Mosin.

Here is picture of special mallet:

 

[Melnic]

http://www.youtube.com/watch?v=LcRzrYqgSsE

Mine will be hard with the surplus ammo if I'm shooting it too fast and its heating up.
But I also had trouble with one where it was hard to close cause of the extractor.

http://www.youtube.com/watch?v=LcRzrYqgSsE

There are some other "Mosin sticky bolt" videos out there, where they put anti seizing compound on the bolt. I did not feel I needed to go that far, Just oil on the bolt cause I wanted to keep it simple.

 

[Smitch521]

It's the nature of the beast. Clean the bejesus out of the cosmo on the bolt and in the chamber. And always have a rubber mallet handy at the range.

NO! It does not have to be this way! I had this very problem, although probably worse. I had to kick the bolt open after every round. There are two remedies to the problem:

1. You have cosmoline in the chamber.- This usually is the case. Take a shotgun brush and soak the chamber in mineral spirits. Put the brush on a section of cleaning rod and chuck it on a drill. Go to town on it.

OR

2. You have a burr in the chamber.- This is the problem I had. Check for scratches on fired casings. From here you can take some fine steel wool / lapping compound and create a tool using a fired casing. Cut a slot in the case and drill a hole through the primer area. Attach this to a drill and insert sandpaper/Steel wool and lapping compound to the slot in the case. Give it a couple spins on the drill.

I had to do the second method and my mosin operates smooth as butter! I can cycle the bolt with my pinky. Don't listen to people who tell you that Mosin's are just naturally rough.

 

[tsmith1499]

I must be lucky. I have never had any issues with any of the Mosin's that I shoot. Of course as Clandestine said, I take them COMPLETELY apart and get rid of the cosmo. before I ever shot any the first time. That includes total dis-assembly of the bolt.

 

[fivepointstar]

its Russian

Kick It
Submerge it in Water
Run over it with a truck
use it to chop wood
build a house with it
cook marshmellows with the bayo

its Russian it will go bang but occasionally clean it

 

[John from MD]

I think that one point in the OP's opening statement was overlooked. "it cycles fine until the last round is fired" He also stated that it is hard to turn iven if he loads just one round in the rifle.

The only difference between a loaded mag and empty mag is that the magazine interupter is pushing up against the bolt and not a round. When the mag is loaded, the interupter pushes against a cartridge keeping the next cartridge down in the mag until the upper one is chambered. As the bolt moves the round into the chamber, the interupter releases the next in line. It's purpose is to prevent rimlock like you can experience on the .303 British Enfield.

It's possible that the interupter has worn and is coming up too high and jaming the bolt. These only cost a couple of bucks and it only takes the removal of the spring screw to change. ( assuming my memory is still working correctly )

 

[clandestine]

I think that one point in the OP's opening statement was overlooked. "it cycles fine until the last round is fired" He also stated that it is hard to turn iven if he loads just one round in the rifle.

The only difference between a loaded mag and empty mag is that the magazine interupter is pushing up against the bolt and not a round. When the mag is loaded, the interupter pushes against a cartridge keeping the next cartridge down in the mag until the upper one is chambered. As the bolt moves the round into the chamber, the interupter releases the next in line. It's purpose is to prevent rimlock like you can experience on the .303 British Enfield.

It's possible that the interupter has worn and is coming up too high and jaming the bolt. These only cost a couple of bucks and it only takes the removal of the spring screw to change. ( assuming my memory is still working correctly )

Excellent Advice. I overlooked it myself when reading.

 

[AssMan]

Yeah I believe it's import corrosive just generic white box ammo and it's only on the last shot

I suggest you keep shooting then.

 

[coopermania]

I think that one point in the OP's opening statement was overlooked. "it cycles fine until the last round is fired" He also stated that it is hard to turn iven if he loads just one round in the rifle.

The only difference between a loaded mag and empty mag is that the magazine interupter is pushing up against the bolt and not a round. When the mag is loaded, the interupter pushes against a cartridge keeping the next cartridge down in the mag until the upper one is chambered. As the bolt moves the round into the chamber, the interupter releases the next in line. It's purpose is to prevent rimlock like you can experience on the .303 British Enfield.

It's possible that the interrupter has worn and is coming up too high and jaming the bolt. These only cost a couple of bucks and it only takes the removal of the spring screw to change. ( assuming my memory is still working correctly )

Very good post John.
I suggest Theneckie you not shoot your rifle and look at the interrupter.