The Russian Mosin Nagant Forum

I have a couple of Mosins from WWII and was wondering if anyone has replaced the bolt springs. I read somewhere you can buy "lighter" bolt springs that will make the action easier to eject and load as well as making it smoother. Old wives tale or truth?

A lighter spring would do those things at the possible expense of unreliable ignition. Just my .

If it ain't broke then don't fix it.

What they said.

billybob123 wrote:I have a couple of Mosins from WWII and was wondering if anyone has replaced the bolt springs. I read somewhere you can buy "lighter" bolt springs that will make the action easier to eject and load as well as making it smoother. Old wives tale or truth?

First off we are presuming you are referring to the firing pin spring. There is no such thing as a bolt spring as far as I know. Get your terminology right or down the way some day it will get you in trouble. Thank god you got some real knowledgeable folks doing the answering for you and they figured it out by the look of things. Now oh you want an answer. Well exactly what they said! I just thought I would pick and tease at you a bit before I let you go. Have a great day! Old weasel Bill

Junk Yard Dog wrote:If it ain't broke then don't fix it.

Word for word, that was my exact thought

Thanks for all the feedback y'all.

billybob123 wrote:I have a couple of Mosins from WWII and was wondering if anyone has replaced the bolt springs. I read somewhere you can buy "lighter" bolt springs that will make the action easier to eject and load as well as making it smoother. Old wives tale or truth?

Cleaning the living hell outa these rifles, the chamber area, is what makes em smooth. Headspace check it. Never saw/ heard of a a "light " spring .

I have heard of that being done....get a few spares and try it out. I doubt you will have ignition issues unless you live in the Arctic....as the springs are overkill given they were designed for very cold temps.
Sticky bolt is more than likely a receiver/barrel area not properly cleared of cosmoline...a shotgun sized brush with solvent can work miracles.

I also 'polish' mating surfaces with 1500 grit wet sandpaper...where the bolt head meets the bolt body and those joining projections on the bolt connector guide bar. Mine cycle empty in the same manner as when loading or removing a fired casing.


It is often a to tight head space if the issues exists only loaded....try a replacement bolt head...and check it properly.

Tight head space?? That's a new one on me. You gotta explain that malady.

When a chambered round is difficult to seat.....head spacing works in two directions with a rimmed round....with the design of the Mosin bolt/bolt head that have often been replaced.

Let me say it differently....on a rimmed round the headspace is controlled by the rim...if the bolt head is not a good match to the bolt or bolt connector it can cause a tight action thru friction....it will fire safely if fully locked but can be a bear to cycle....experimenting with another bolt head can relieve this issue.

Gotcha, thanks. A good check of headspacing will fix that.

reiver wrote:When a chambered round is difficult to seat.....head spacing works in two directions with a rimmed round....with the design of the Mosin bolt/bolt head that have often been replaced.

Let me say it differently....on a rimmed round the headspace is controlled by the rim...if the bolt head is not a good match to the bolt or bolt connector it can cause a tight action thru friction....it will fire safely if fully locked but can be a bear to cycle....experimenting with another bolt head can relieve this issue.

You're still describing a rifle that has varnish in the chamber/ sticky bolt.

"You're still describing a rifle that has varnish in the chamber/ sticky bolt."

Sticky bolt can come from more than varnish in the chamber.... many Mosins have replacement bolts/bolt heads. Bolt heads that were broken in by another receiver that can lead to lugs seating unevenly (more pressure/contact on one lug) that slightly tilts the bolt head leading to sticky bolt thru. uneven friction.
A tighter than normal spec head space as articulated above attributed to a few factors.

You can have a spotless receiver and barrel and still have a sticky bolt.

reiver wrote:"You're still describing a rifle that has varnish in the chamber/ sticky bolt."

Sticky bolt can come from more than varnish in the chamber.... many Mosins have replacement bolts/bolt heads. Bolt heads that were broken in by another receiver that can lead to lugs seating unevenly (more pressure/contact on one lug) that slightly tilts the bolt head leading to sticky bolt thru. uneven friction.
A tighter than normal spec head space as articulated above attributed to a few factors.

You can have a spotless receiver and barrel and still have a sticky bolt.

Have you tried switching bolt heads from another rifle ?

steelbuttplate wrote:

reiver wrote:"You're still describing a rifle that has varnish in the chamber/ sticky bolt."

Sticky bolt can come from more than varnish in the chamber.... many Mosins have replacement bolts/bolt heads. Bolt heads that were broken in by another receiver that can lead to lugs seating unevenly (more pressure/contact on one lug) that slightly tilts the bolt head leading to sticky bolt thru. uneven friction.
A tighter than normal spec head space as articulated above attributed to a few factors.

You can have a spotless receiver and barrel and still have a sticky bolt.

Have you tried switching bolt heads from another rifle ?

Yes, then checked headspace, and found an improvement.....another way to check is coloring the contact areas of the bolt head lugs and cycling the action. If you note a great disparity in the removed ink (marker) then there is an imbalance....if it is great it will cause a sticky bolt when fired.
I do this with a snap cap or blank round.
I do not like removing metal from the lugs beyond a light polish with a 1500 grit this being a hardened area.
BTW, I simply buy bolt heads on line and keep a few around....experiment with fit/finish etc...until everything cycles smoothly and has a tested head space. Even passing a head space test does not mean the lugs engage properly.
The extractor can also be an issue....many were pretty crudely replaced.

p.s. I know this may be frowned upon as a modification but I shoot my rifles regularly ….and....the original (refurbed or not) bolt head is still available.

For examples sake..... I just swapped out three bolt heads on three different rifles....each one passed the go/no go head space gauge test and I think I'll keep two of them swapped as is...they cycle smoother when fired (snap cap).
BTW, I just bought a few on ebay ( I do not sell these, no affiliation)...they were not refurbed as the bolt face was full sized where it contacted the brass and all of them had tighter spec firing pin holes...these came with the ejector in place.... two will replace the originals.

I replaced my springs with new-made springs and the sticky-bolt syndrome disappeared and there have been no failures to fire or extract.
Jon

musketjon wrote:I replaced my springs with new-made springs and the sticky-bolt syndrome disappeared and there have been no failures to fire or extract.
Jon

Nice.… easy fix. 'Sticky bolt' can be the result of a few dif things besides cosmoline in the lug area.