Finnish Mosin barrel interchangeability

[Slamfire]

Do what you can to clean the barrel, but if your rifle barrel is as rusted as a Russian capture Mauser I own, the only solution is a new barrel.

I soaked the German Mauser in Sweets, used JB bore paste, then steel wool, and that barrel remains dark. When I shot it, I could tell the interior was eroding away! You could see the rifling change at the throat! It would group on an 8.5 X 11 inch sheet of paper at 100 yards. That was about it.

I did bed the rifle, installed a taller front sight, but I have done nothing else for the thing. It is just not worth it to spend $400 for a new barrel, and I am not interesting in spending the time screwing on a old surplus barrel.

 

[boom boom]

I've got some Wipeout on order. I've never used it before, but I planned to use that initially -- plug the barrel, soak for a day, rinse and repeat as needed. My general cleaner is Tetra Action Blaster, which I've been fairly happy with in my limited experience.

I've never used bore paste or electrolysis, but with some research I'd be willing to try.

I dig the old milsurps as well and certainly more for their practicality as shooters than for any collector value, especially for hunting. But I don't have much experience with them yet, hence my questions on this board.

The electrolysis method is basically going to the hardware store and buying a few items totalling maybe $20-30 bucks. Outers used to sell a system called Foul Out that was about $100 and had the electrolysis solution pre made for either lead or copper fouling. Basically you are plating an electrode with the fouling while the anode (your barrel) donates it to the steel rod in the barrel. You put in a steel rod somewhat smaller than the bore with insulators such as electricians tape to keep the rod from grounding out. The chamber is usually plugged with a rubber stopper, you add the electolytic solution to the muzzle end, and then you attach a negative clamp to the rod and a positive clamp to the battery. One variant is to use a battery and a cheap flashlight using the flashlight in the circuit to tell you time to quit. The other uses a more sophisticated setup with a low voltage charger as the source. There are replica formulas for the Foul Out solutions floating around.

The safest way for electrolysis is to use a battery setup as it is almost impossible to get enough current flow to damage a barrel, the other method is to use a low voltage charger of some sort. Even the most fouled barrels take about 10-15 minutes at max and it strips it to gray metal. However, if you have layered fouling, you may have to repeat the treatment a couple of times alternating between powder fouling removal solvent and then electrolysis. The major issue is that it does generate gases that need to be dispelled so best to do so outdoors with no flame source around and you really should take the action out of the stock to do it. It can be messy and does involve semi-noxious chemicals so if you don't like chemistry then best to avoid it.

Bore paste is safe, easy and wears out your arm. JB Bore paste goes for about ten bucks or so and you can use an old worn bore brush not suitable for other issues. There you follow the directions and are basically doing a mild version of lapping the barrel--the regular stuff is gray and is a variant of jewelers rouge used to polish jewelry. The other is red (JB Bore Brite) and used after the gray stuff to add some slickness to the bore. Make sure to thoroughly clean the bore after using either as if you fire a bullet through the stuff, it could get exciting or cause wear where you did not want it. You do not have to dismount the action to do this.

A few folks reported using this as a diy firelapping technique but it is the usual heard it on the internet so I would advise using the std. firelapping techniques either with preloaded ammo or handloads if that floats your boat.

Then you can combine methods mentioned above and really crappy barrels for which there is no cheap replacement are candidates for this where there is little to lose if you fail. One can never have too many tomato stakes.

 

[boom boom]

OP, I'm here to testify that you shouldn't give up on that barrel yet.
I have a 1930 Izzy 91/30that looked just a bit better than your barrel. I spent 4 days cleaning it - not 4 days straight, but 4 days of messing with it after it soaked.

I used Ed's Red on a patch, then scrub. Then wet with Ed's Red and leave it for a few hours.

Patch that out, and switch to Hoppes, do the same circus.

Then switch to copper solvent, repeat.

Then go and start the carousel again.

I ended up with a dark, pitted bore with fair rifling that slugged at .315". I shoot .316 cast from it, into 2-3 MOA at the monthly club military match.
I could probably do better, but the trigger is horrid.

Did you make your own Ed's Red or buy the premade stuff from Brownells? I've made the Ed's Red without the lanolin added as that is a pain to make but wondering if the premade stuff is better.

 

[Hooda Thunkit]

Hooda -- what do you mean that the trigger is "horrid?" Heavy? Long travel distance? I don't know what's standard on these old Mosins, but the trigger on mine is surprisingly heavy and has a long pull. I'd wondered if I could modify the spring to alleviate some of that, sometime down the road.

Yes, heavy with loooonnnngggg travel, and creepy at engagement.

Yes, that's pretty much standard with old Mosins.

Yes, you can modify to a surprisingly decent trigger. Not wonderful, but useable. Or, you can replace it completely with one of the trigger a from Smith-sights.

One of the THR members and infrequent poster is Mr. Smith of Smith Sights http://smith-sights.com/
He has a lot of info on his site about fixing up Mosins and how to improve their triggers including videos. Pretty useful overall for Mosin knowledge and some key parts.

This ^^^
First, clean the barrel, or at least clean at it. Find out if it will hit what you shoot at.
Then, look up Smith-sights. He knows whereof he speaks.

 

[Hooda Thunkit]

Did you make your own Ed's Red or buy the premade stuff from Brownells? I've made the Ed's Red without the lanolin added as that is a pain to make but wondering if the premade stuff is better.

Oh, I forgot this one.

I made my own, without the lanolin. I made a gallon. If I live long enough to use this gallon, I'll make a quart next time.

It works fine, if you remember it's basically a powder/carbon solvent with lubricant. I've never tried the premade, and TBH didn't know it was available.

 

[handsonaudio]

Do what you can to clean the barrel, but if your rifle barrel is as rusted as a Russian capture Mauser I own, the only solution is a new barrel.

I soaked the German Mauser in Sweets, used JB bore paste, then steel wool, and that barrel remains dark. When I shot it, I could tell the interior was eroding away! You could see the rifling change at the throat! It would group on an 8.5 X 11 inch sheet of paper at 100 yards. That was about it.

I did bed the rifle, installed a taller front sight, but I have done nothing else for the thing. It is just not worth it to spend $400 for a new barrel, and I am not interesting in spending the time screwing on a old surplus barrel.

Thanks, Slamfire. I'll do what I can to clean it, shoot it as safely as I can, and then go from there depending on the results. I do still acknowledge the possibility that the rifle may not be salvageable, but if there's one takeaway from this thread it's that my odds are better than I originally thought.

 

[illinoisburt]

As an update, this barrel was a little better but not too far off from what yours looks like prior to soaking, scrubbing, and a little polishing. Been maybe 11 or 12 years ago now. Shows some small pits and it is a bit dark. Hasn't had any further deterioration.

Shoots around 2 to 3 inch groups with 203 grain silver bear soft points with the irons on bags. 1970s surplus light ball is 4 to 5. I'm sure better ammo would improve on it, as would maybe some trigger work and improved sights. Works just fine for my use as-is.

 

[illinoisburt]

I've got some Wipeout on order. I've never used it before, but I planned to use that initially -- plug the barrel, soak for a day, rinse and repeat as needed. My general cleaner is Tetra Action Blaster, which I've been fairly happy with in my limited experience.

I've never used bore paste or electrolysis, but with some research I'd be willing to try.

Wipeout should take care of any old powder or copper. If it still looks caked with flakes of carbon or rust, evaporust is generally safe and easy to use without a lot of special set-up. About $10 for a large bottle at most automotive and hardware stores. Plug and fill, let sit for a few hours or overnight. When the barrel is down to bare metal, give it a good cleaning, polish as needed, and lightly oil.

 

[boom boom]

Do what you can to clean the barrel, but if your rifle barrel is as rusted as a Russian capture Mauser I own, the only solution is a new barrel.

I soaked the German Mauser in Sweets, used JB bore paste, then steel wool, and that barrel remains dark. When I shot it, I could tell the interior was eroding away! You could see the rifling change at the throat! It would group on an 8.5 X 11 inch sheet of paper at 100 yards. That was about it.

I did bed the rifle, installed a taller front sight, but I have done nothing else for the thing. It is just not worth it to spend $400 for a new barrel, and I am not interesting in spending the time screwing on a old surplus barrel.

Wipeout should take care of any old powder or copper. If it still looks caked with flakes of carbon or rust, evaporust is generally safe and easy to use without a lot of special set-up. About $10 for a large bottle at most automotive and hardware stores. Plug and fill, let sit for a few hours or overnight. When the barrel is down to bare metal, give it a good cleaning, polish as needed, and lightly oil.

Never quite had the guts to use evaporust or the like in a barrel. I have used it to good effect on other items.

 

[illinoisburt]

Never quite had the guts to use evaporust or the like in a barrel. I have used it to good effect on other items.

It's not caustic like acid or vinegar, so no really danger of creating any damage in the bore beyond what is already there. It will however remove rust bluing, so don't want to soak the outside of the barrel. It's one of the better and safer rust removing products available. Of course rust is not copper or powder residue so kind of limited applications with firearms beyond restorations.

 

[boom boom]

It's not caustic like acid or vinegar, so no really danger of creating any damage in the bore beyond what is already there. It will however remove rust bluing, so don't want to soak the outside of the barrel. It's one of the better and safer rust removing products available. Of course rust is not copper or powder residue so kind of limited applications with firearms beyond restorations.

I have used Blue Wonder + Kroil in my rust removal from some barrels which generally does not affect the bluing so I was curious about the evaporust in that application.

 

[handsonaudio]

The electrolysis method is basically going to the hardware store and buying a few items totalling maybe $20-30 bucks. Outers used to sell a system called Foul Out that was about $100 and had the electrolysis solution pre made for either lead or copper fouling. Basically you are plating an electrode with the fouling while the anode (your barrel) donates it to the steel rod in the barrel. You put in a steel rod somewhat smaller than the bore with insulators such as electricians tape to keep the rod from grounding out. The chamber is usually plugged with a rubber stopper, you add the electolytic solution to the muzzle end, and then you attach a negative clamp to the rod and a positive clamp to the battery. One variant is to use a battery and a cheap flashlight using the flashlight in the circuit to tell you time to quit. The other uses a more sophisticated setup with a low voltage charger as the source. There are replica formulas for the Foul Out solutions floating around.

The safest way for electrolysis is to use a battery setup as it is almost impossible to get enough current flow to damage a barrel, the other method is to use a low voltage charger of some sort. Even the most fouled barrels take about 10-15 minutes at max and it strips it to gray metal. However, if you have layered fouling, you may have to repeat the treatment a couple of times alternating between powder fouling removal solvent and then electrolysis. The major issue is that it does generate gases that need to be dispelled so best to do so outdoors with no flame source around and you really should take the action out of the stock to do it. It can be messy and does involve semi-noxious chemicals so if you don't like chemistry then best to avoid it.

Bore paste is safe, easy and wears out your arm. JB Bore paste goes for about ten bucks or so and you can use an old worn bore brush not suitable for other issues. There you follow the directions and are basically doing a mild version of lapping the barrel--the regular stuff is gray and is a variant of jewelers rouge used to polish jewelry. The other is red (JB Bore Brite) and used after the gray stuff to add some slickness to the bore. Make sure to thoroughly clean the bore after using either as if you fire a bullet through the stuff, it could get exciting or cause wear where you did not want it. You do not have to dismount the action to do this.

A few folks reported using this as a diy firelapping technique but it is the usual heard it on the internet so I would advise using the std. firelapping techniques either with preloaded ammo or handloads if that floats your boat.

Then you can combine methods mentioned above and really crappy barrels for which there is no cheap replacement are candidates for this where there is little to lose if you fail. One can never have too many tomato stakes.

Tomato stakes -- haha. I've also got some bore paste and extra brushes on order. I'll give that a shot after the Wipeout has done its thing. When all is said and done, I'm not worried about ruining a good rifle. It was cheap enough that makes a good testbed for this kind of stuff, especially as I'm learning.

RE: Evaporust, I wouldn't be afraid to try that either, even if it removes blueing. I've done some spot-bluing before with success and was already planning on re-blueing the Mosin everything else worked out.

 

[351 WINCHESTER]

I had an old Enfield that I thought the barrel was toast. It looked much worse than your rifle. I bought some J & B bore paste & went to work. At first it felt rough as a corncob. I worked on it for about 3 days, wearing out about 3 or 4 bronze brushes. She shoots like a charm now. She likes to be shot dirty, so I never clean the barrel. I think some copper filled in some of the pits.

 

[Hooda Thunkit]

...She likes to be shot dirty, so I never clean the barrel. I think some copper filled in some of the pits.

My M39 Finn is the same. I shoot gas checked lead through it (Lee C312-185-1R )andI know I've fired at least 250 rounds through with no cleaning.
I have a 1930 Izzy 91/30 that is the same. I've fired hundreds of the NOE equivalent of the 312299 (but in .316 dia) with nothing but a wet patch every year or so, followed by dry patches. And this with a dark, pitted bore.

I'm running these at about 1700 fps.

 

[handsonaudio]

After having attacked the barrel with Wipeout (3-4 soaking sessions in addition an an overnight), electrolysis, then JB bore paste, I think I've made as much difference as can be made with this Mosin barrel. By eye, the barrel is MUCH cleaner than before. However, all of this did reveal some unmistakable pitting near the muzzle end.

The first photo is a side by side ("before" on the left, "after" on the right).

 

[boom boom]

After having attacked the barrel with Wipeout (3-4 soaking sessions in addition an an overnight), electrolysis, then JB bore paste, I think I've made as much difference as can be made with this Mosin barrel. By eye, the barrel is MUCH cleaner than before. However, all of this did reveal some unmistakable pitting near the muzzle end.

The first photo is a side by side ("before" on the left, "after" on the right).

View attachment 853509 View attachment 853506 View attachment 853507 View attachment 853508

With the pitting near the muzzle end, you can fire a few fmj rounds and it will probably fill in somewhat. Pitting on the lands (raised portion) is always a bit more problematic but it may smooth out. Make sure to check the crown of your barrel before giving up on accuracy as it may very well need to be recrowned.

One thing that you can do that is fairly cheap is if the pitting is affecting accuracy but is mainly at the muzzle end for the last 2-3 inches is to counterbore the rifle. The Russians did this quite often on their rifles and if you do want to preserve a collectible combo such as your receiver and the barrel, it will keep the front sights, the outside look, etc. of the m27 but should improve accuracy. Another if you do not care about the barrel or front sights is to cut the barrel off to remove the damaged area nearest the muzzle.

 

[handsonaudio]

Thanks for the suggestions. I'll try a few rounds of fmj and see what she can do, though I don't know how soon I'll get the chance. After that I'll decide what to do.

I'd honestly be open to either the counter-boring or just chopping the barrel down.

 

[Hooda Thunkit]

That (cleaned) bore doesn't look all that different from a 1930 Izzy 91/30 that I shoot regularly.

I can get 2-3 MOA with home-cast lead handloads, and close to that with pulled 147gr surplus and 13gr Promo.
I shot it in the club Military Bolt-gun matches, and would score in the 270-280 range.

Don't give up on it.

 

[illinoisburt]

Thanks for the suggestions. I'll try a few rounds of fmj and see what she can do, though I don't know how soon I'll get the chance. After that I'll decide what to do.

Suggest your testing should be with new production ammo rather than older surplus. The surplus can have lots of variation from good to downright awful, so better to leave that variable out.

 

[theotherwaldo]

I've swapped the triggers and sears in most of my Mosin shooters for some that were made for M39s. I also added slack-control springs to most, although I lost one during installation. They sure can fly!
Very easy to reverse the mod, of course.

 

[illinoisburt]

handsonaudio did you a chance to shoot it yet?

 

[handsonaudio]

Sorry for reviving the old thread, but I just now saw your last question, Burt. I did get a chance to shoot the Mosin but under less than ideal circumstances. She had roughly 6" groups at roughly 50 yards without a proper bench rest. My inexperience as a shooter should be taken into account as well. All in all, I think it proved that she could hit paper but that's about it.

My focus has since shifted to other guns and other projects, but I'd like to give this Mosin another chance one of these days. I wouldn't mind trying a few improvements, even irreversible ones, since I the gun can't really lose any more value than it currently has. Trigger mods would help as would bedding the stock, I think. With the boroscope, the pitting really extends all the way down the barrel so I doubt cutting off the final 6" or so would help much, though I wouldn't be above a re-crown or even counter bore. I don't know yet. If I make any progress, I'll be sure to post the results here.

 

[handsonaudio]

Here's what the current crown looks like. I don't think it's too bad, TBH. What do you guys think?

 

[theotherwaldo]

The crown doesn't look too bad except for a minor ding.

The bore, on the other hand, looks like it might profit from a counterbore.

 

[handsonaudio]

Well, I've realized those close-up cell phone photos aren't worth much. I took another look under good lighting with a 30X loupe. Geez..... Now I know how Tesla felt the first time he saw unboiled water under a microscope. Turns out, all of my guns could use re-crowning, lol.

This Mosin would definitely benefit from a re-crown, if not a counter-bore or barrel shortening. At close-up, the crown is pretty pocked and the rifling is almost non-existent.