Mosin nagant quick saftey check

dieselcamino · August 24, 2012, 04:09 PM

hey guys, Just got my first mosin nagant (for free) shot it already and had a good time, only after 15-20 rounds the bolt started jamming up on me. took the bolt apart and cleaned out all the nasty old cosmoline. but before bringing it out to the field again just wanted to check a few things.

1. the firing pin depth is flush with the back of the safety knob and matched up with the two engraved lines, so that is all good correct?

2. By dissembling the bolt i haven't effected the head space at all correct? and if it hasn't blown up in my face yet the headspace should be ok? (i'm waiting on a friend with one of those go/nogo tools)

thanks-

Scimmia · August 24, 2012, 04:28 PM

Correct and Correct. Make sure to clean the chamber out very, very well, as that's a more common area for things to stick after heating up.

dieselcamino · August 24, 2012, 04:57 PM

good to hear, one other thing i found strange was that every once in a while i would find an ejected case that had a small crack running down the body of the shell right where it necks down to the projectile. I was using wolf copper washed ammo. worked good otherwise and the bore seems pretty clean and free of rust and pitting

tobnpr · August 24, 2012, 06:15 PM

The FP depth should be OK, but you cannot be sure. If a different FP has been inserted at some point, they may be irrelevant. Best to check with the FP gauge tool, most come with it; since yours did not they're cheap and easy to find.

Cleaning the bolt may or may not have solved your problem. Be sure to clean the chamber very well. The lug recesses are tough to get into, but mandatory- or you'll have another bad range session.

If your hard bolt lift persists, google "Mosin sticky bolt"...cosmoline can be extremely hard to get out of the chamber. Even a small amount will re-surface when the chamber gets hot- and the bolt will stick again. A 12 ga. chamber brush chucked into a drill can help clean it up if all else fails.

dieselcamino · August 25, 2012, 12:00 AM

I'm somewhat well versed in the ways of cosmoline, having cleaned 5 or 6 sks's from the crate for friends, i have always gone for the heat gun and brake parts cleaner method. I feel i have gotten it all out to free up the bolt, I'm more worried about the headspace of the gun, not having adjusted it but i have just recently learned of the damage that can occur from it not being spot on.

01SVTvert · August 26, 2012, 05:50 PM

Headspace is determined on a Mosin by the entire bolt face being replaced. You cannot change it by disassembly unless you put a different bolt face onto your bolt body.

The reason that is started sticking after 15-20 rounds was the barrel and chamber heated up and dried cosmo that has been in the chamber for 50+ years softened up enough to grip the case. Google mosin sticky bolt if you want to see solutions but a 20 ga brush and a good cleaning of the chamber will remedy it. You can chuck it in a cordless drill if you want also.

Some cases split, it would not be due to firing pin protrusion but could be from a bad chamber. Use a good light and look for damage in the chamber at the shoulder after cleaning. How many of the rounds split? Does it do it with different ammo? Sometimes it is the ammo so I wouldnt worry until you have tried otehr ammo.

August 24, 2012, 04:09 PM	#1
dieselcamino Junior Member Join Date: August 24, 2012 Posts: 3	Mosin nagant quick saftey check hey guys, Just got my first mosin nagant (for free) shot it already and had a good time, only after 15-20 rounds the bolt started jamming up on me. took the bolt apart and cleaned out all the nasty old cosmoline. but before bringing it out to the field again just wanted to check a few things. 1. the firing pin depth is flush with the back of the safety knob and matched up with the two engraved lines, so that is all good correct? 2. By dissembling the bolt i haven't effected the head space at all correct? and if it hasn't blown up in my face yet the headspace should be ok? (i'm waiting on a friend with one of those go/nogo tools) thanks-

August 24, 2012, 04:28 PM	#2
Scimmia Senior Member Join Date: May 19, 2011 Location: Eastern IA Posts: 428	Correct and Correct. Make sure to clean the chamber out very, very well, as that's a more common area for things to stick after heating up.

August 24, 2012, 04:57 PM	#3
dieselcamino Junior Member Join Date: August 24, 2012 Posts: 3	good to hear, one other thing i found strange was that every once in a while i would find an ejected case that had a small crack running down the body of the shell right where it necks down to the projectile. I was using wolf copper washed ammo. worked good otherwise and the bore seems pretty clean and free of rust and pitting

August 24, 2012, 06:15 PM	#4
tobnpr Senior Member Join Date: August 1, 2010 Location: Tampa Bay Posts: 4,556	The FP depth should be OK, but you cannot be sure. If a different FP has been inserted at some point, they may be irrelevant. Best to check with the FP gauge tool, most come with it; since yours did not they're cheap and easy to find. Cleaning the bolt may or may not have solved your problem. Be sure to clean the chamber very well. The lug recesses are tough to get into, but mandatory- or you'll have another bad range session. If your hard bolt lift persists, google "Mosin sticky bolt"...cosmoline can be extremely hard to get out of the chamber. Even a small amount will re-surface when the chamber gets hot- and the bolt will stick again. A 12 ga. chamber brush chucked into a drill can help clean it up if all else fails.

August 25, 2012, 12:00 AM	#5
dieselcamino Junior Member Join Date: August 24, 2012 Posts: 3	I'm somewhat well versed in the ways of cosmoline, having cleaned 5 or 6 sks's from the crate for friends, i have always gone for the heat gun and brake parts cleaner method. I feel i have gotten it all out to free up the bolt, I'm more worried about the headspace of the gun, not having adjusted it but i have just recently learned of the damage that can occur from it not being spot on.

August 26, 2012, 05:50 PM	#6
01SVTvert Junior Member Join Date: August 11, 2012 Posts: 8	Headspace is determined on a Mosin by the entire bolt face being replaced. You cannot change it by disassembly unless you put a different bolt face onto your bolt body. The reason that is started sticking after 15-20 rounds was the barrel and chamber heated up and dried cosmo that has been in the chamber for 50+ years softened up enough to grip the case. Google mosin sticky bolt if you want to see solutions but a 20 ga brush and a good cleaning of the chamber will remedy it. You can chuck it in a cordless drill if you want also. Some cases split, it would not be due to firing pin protrusion but could be from a bad chamber. Use a good light and look for damage in the chamber at the shoulder after cleaning. How many of the rounds split? Does it do it with different ammo? Sometimes it is the ammo so I wouldnt worry until you have tried otehr ammo.