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Discussion Starter · #1 ·
1946 Izzy M44 project rifle.
This was a $50 bubba M44, minus the bayonet and ground off lug, snatched up to serve as an ammo burner on the range. Just another short carbine to use and abuse, it is receiving in excess of $300.00 in new clothes inclusive of a Boyd’s walnut stock with Devcon pillar post bedding, Mojo rear sight, Truglo front blade, mercury recoil suppression tube, Limbsaver magnum pad and a hundred hours or so of work.

The original stock was nothing to get excited about being just average with handling dings and dents. The metal, however, appeared to be unissued and unused with no wear at all and no copper fouling in the pristine bore.

1946 must have been a rough time in Russian gun factories. I conjure images of slave and conscript labor along with herds of children using hand files …
The front sight was so crudely made with the base dovetail being cut on an angle that canted the whole sight and the post being drilled off center and bent to compensate that it just had to be replaced.

The bolt is extremely bright with no signs of wear at all. The firing pin didn’t even have any powder residue in the hole or on the pin. It was, however, extremely tight and stiff when cycled.
Having thoroughly cleaned and polished it, and with minimal lubrication, I took it out to the range to get the sights adjusted.
Warming it up with a good sixty or more rounds, cycling the bolt became progressively more and more difficult and flipping it open required a good hard smack with the palm to get it open.
I was beginning to suspect a chamber throat gummed up with poly and lacquer but the copper washed steel case 7.62x54R I was using is relatively clean and leaves no deposits.
It eventually got to the point where the bolt wouldn’t open and I had to put it away.
When I got home, it was still pretty warm and the bolt still stuck. It required a smack with a large rubber mallet to finally get it open and remove the empty shell. The empty showed no signs of sticking or deformity and fresh shells fit easily into the chamber.

The bolt, with no bullet in the gun, would bind and stick badly when cycled.
Disassembled for close and magnified inspection, the problem became quite clear.
The various mating surfaces that turn against each other were very roughly cut with sharp and jagged edges. Several of these areas had coarse file marks visible indicating these areas were hand formed with a coarse file and never polished down. The parts were grinding and grating against each other rather than easily slipping by. Without copious lubrication, they simply bound up to the point of complete lockup when hot. Compared to a well worn and loose bolt on the M38, which despite its beat up appearance is very smooth, this bolt was positively crude in manufacture.

Continued below ..
 

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Discussion Starter · #2 ·
Polishing the visible surfaces of the bolt to a bright mirror finish with the Dremel polishing wheel and fine compound was easy for appearance sake. Polishing the rough file cut surfaces required a bit more work to smooth out the file marks and the rough edges.
Using the polishing wheel on medium speed and with a good amount of compound, work all the mating surfaces that turn against each other until bright and smooth.
Do the same to the two bearing surfaces on the receiver that the bolt turns against to cock.
These areas were found to be just as rough cut as the bolt with file marks in them!

Continued below ..
 

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Discussion Starter · #3 ·
The area on the bolt that was causing the majority of problem was the cocking notch.
As you rotate the back portion of the bolt to cock and decock, you can see the little protrusion that locks into the little notch on the bolt body. This notch appeared to have been hand cut with a file and was very sharp and jagged. The corresponding protrusion was catching and digging in here when cocking. These two parts required quite a bit of polishing to finally smooth out until cocking became a fluid motion without binding.
 

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Discussion Starter · #4 ·
There isn’t a whole lot you can do with the sear but running the polishing wheel over the edges to smooth and round them a little does improve trigger let off. It does considerably smooth out a gritty or grinding trigger pull.

The big difference comes from MolyFusion. http://www.shootersolutions.com/mol12ozkit.html
The smallest kit they sell is enough to do hundreds of projects and I have quite a bit left after treating several guns.
MolyFusion is, as they say, grease on steroids and a super lubricant.
While it does not chemically bind to the plating on the bolt, it does create enough bonding to provide a smooth surface.
Apply a small dab of MolyFusion paste to all surfaces that rub against one another and cycle the bolt repeatedly to distribute and work in. Let it sit for several days to accomplish as much permanent bonding as possible then disassemble and wipe off any excess. Areas where it has chemically bonded to the metal will change color slightly, especially on the bare steel of the receiver where it will bond completely. Wipe a small amount inside the receiver bolt channel where the bolt rides against the receiver. Apply a dab to the sear.
Assemble the bolt and lightly lubricate all parts that mate and rub against each other with MolyFusion oil. The oil contains a small amount of moly and while not as chemically potent as the paste concentrate, it is a super lubricant.

After a few days, when you see color change from the MolyFusion, the bolt will now cycle silky smooth and trigger let off will be much smoother with no drag. Trigger pull will not be any lighter nor hair trigger but it will be smoothed out considerably.

Results have proven satisfactory to the point where I will have to eventually get around to doing the same to all the Mosin bolts!
 

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I'll have to re-examine mine to find those surfaces in your pictures that mate diagonally. I feel mine do a 3 step ratched as I rotate the bolt into lock position. The first click is encountered as the bolt starts down, and I smoothed that by minor filing to get the surfaces to mate at a 45 degree with at least a small flat spot on the bolt and receiver. My initial observation was that the bolt had a flat surface and the receiver was a jagged point. With a little filing that first notch is a little smoother, but I can't find where the next two sticky points are coming from.

I'll be watching this thread closely.

KKKKFL
 

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Discussion Starter · #7 ·
When I say "coarse file marks" I mean you could actually see the grooves left by a very heavy and deep cutting file!
This bolt looked like it was brand new out of the factory with no hint of wear at all.
With adequate lubrication, it was ok but stiff and sticky.
I didn't give it much thought other than cleaning it thoroughly with carb cleaner and alcohol and then very lightly oiled it to keep it from rusting.
Warming it up quite thoroughly to test fire the new sights and stock made the problem apparent when she locked up tight.
Only then did I make a close examination with a magnifying lens and comparison to a well worn bolt to see why.

Naturally, weather didn't cooperate the other day when I wanted to take it out for another test drive and I'm itching to see the results.
As it stands right now, it is the smoothest Mosin bolt and trigger in the collection. Damned pretty too!
 

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My M44 is difficult to move when lifting the bolt handle up to cock, or when pushing it down to complete the motion prior to firing. It slides back and forth just fine. Sounds like I need to have someone do some polishing on it as well. Thanks for the helpful suggestions. :D
 

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Thanks for the info. Luckily all the bolts on my Mosins function smooth. But as the collection grows:rolleyes: a binding bolt may come up. And now we have a well thought out and performed solution. To add My "49" M44 has the best finish and is one of my most accurate Mosins (second only to my M39).
 

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Hmmm....None of my 80 Mosins needed modification.

Wonder why?

Gary :D
 

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If the bolt stiffness were caused solely by rough machining, why would it increase as the rifle heated up? The surfaces do not change with heat (normal operating temps).

There must be something else going on here.
 

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Discussion Starter · #13 ·
It's the current batch of copper washed surp Yugo ammo we have been going through which is proving problematic in everything, especially the SVT40. Dirty and leaving a lot of residue in the chamber sticking the empties.

Physical function of the bolt is markedly improved, as well as a really sweet sear, but does little to correct for this ammo gumming up extraction.
 

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I followed the instructions and plolished the cocking surfaces, which made a large difference. I took the processes described a step further putting Molypaste on all surfaces and operating the bolt repeatedly. This was wiped off after a couple days and my M44 now has a smooth action. One other thing I noticed was placing a dummy cartridge on the face of the bolt and working it in so it would seat, I found the the edges opposite from the extractor spring were very sharp. I took a jewelers file and rounded the edge ever so slightly. This removed that last burr that shows up as you lock the bolt down. It cycles Copperwashed, Brass, and Steel cases alike very smoothly now.

KKKKFL
 

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Discussion Starter · #17 ·
Trimming three coils off the firing pin spring made a world of difference in cycling the bolt.
It tended to get very stiff and hard to open after quite a few rounds, to the point of blistering hot, and required a good smack to open.
Taking the spring down had no impact on the firing pin hitting hard enough to pop them off.
It did really smooth out bolt operation!

I am bugging http://www.davidtubb.com/ to make a Speedlock pin and spring set for Mosin.
I used one in a balky K98 and it is OMG awesome.
As advertised, lock time is lightning fast.
I have no doubt the same thing in a Mosin would make a world of improvement.
Email and bug them!
 

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The parts expand when heat builds up making a rough contct even rougher. That's why the bolts eventually lock up. If the rifle has a chance to cool down it should slide less roughly because the metal parts contract. In effect the metal pieces act like gear teeth that may even have very different coefficients of expansion.

Joe McD
 

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Trimming three coils off the firing pin spring made a world of difference in cycling the bolt.
It tended to get very stiff and hard to open after quite a few rounds, to the point of blistering hot, and required a good smack to open.
Taking the spring down had no impact on the firing pin hitting hard enough to pop them off.
It did really smooth out bolt operation!

I am bugging http://www.davidtubb.com/ to make a Speedlock pin and spring set for Mosin.
I used one in a balky K98 and it is OMG awesome.
As advertised, lock time is lightning fast.
I have no doubt the same thing in a Mosin would make a world of improvement.
Email and bug them!
I have done this as well.

This has good info............ http://www.surplusrifle.com/shooting2006/improvingm44carbines/index.asp
 
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