took it apart today

[shaper]

Had my Mossin Nagant out and decided it was time for a deep clean. After a while I finally found out how to get it into a pile of parts. I couldn't get the barrel clean, every piece of cleaning patches I ran through the barrel came out black. I was shocked, there was cosmoline every where I opened it up. I need to find some of those long Q tips on a stick to get down into the breach and barrel. I hear diesel fuel works on the cosmoline, good thing I have some on hand, my air compressor has a diesel engine.
I haven't had the rifle very long, got it from a gun show. Well, it looked clean from the outside when I got it.

[WallyM3]

If the diesel fuel seems slow at attacking the goo, give Naphtha a try.

And don't forget pipe cleaners. Real handy in any shop.

[birddog1148]

I used a turkey fryer with water and Dawn to clean several. Not quite boiling water but too hot to put my hand in. Cleaned those old rifles right up and the hot metal makes the water evaporate real fast. The cosmoline pushed out of the barrel looking like a rubber fishing worm.
Just the metal, not the wood.

[draidt]

Mineral spirits, Take the bolt apart and just let it soak for a day or two, BrakeKleen in the green can works very well. Remove the trigger and magazine assembly and soak that as well. Ammonia and water 50/50 mix will get the barrel clean with due diligence. There are many videos on You Tube dealing with this. I have cleaned up 9 Mosin's and it really is not rocket science just patience.

[LUCKYDAWG13]

3" 4 ft piece of pvc with a cap on one end put barrel in soak in mineral spirits
have fun

[spfd1903]

Bought an M44 several years ago in the same condition. The cosmoline in the barrel was so thick and hard I could not force a dowel rod down it. Had a 6" dia. x 3 ft. fence post driver that I filled with kettle after kettle of boiling water and kept dipping the barrel in. The stuff in the barrel finally softened up to where I could push it out. Half cup of kerosene and a lot of rags finished the job. For $79 worth of rifle, it was time well spent.