I have a Mosin-Nagant M44 carbine I got for about 50 bucks, so its not a huge problem for me - but it's the principle of the thing.  The barrel is severely darkened and it looks like it may be somewhat pitted.  No matter how much I clean it the bore is still dark and nasty looking and patches come out dirty.  Anyone have any reccomendations?  Someone told me to try PB Blaster penetrating oil.  I've got nothing to loose but......

Try this it works good, [url]http://www.midwayusa.com/rewriteaproduct/137203[/url]

Use the "homemade electronic bore cleaner"

Work's wonders.

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Clean it with hot water and dishwashing liquid.Put the hot water and soap in a pan,set the pan in the floor,stick the muzzle in the water/soap and pump the patched cleaning rod back and forth in the bore.The hot water will get the barrel pretty warm and break alot of funk loose.Do not pull the rod and patch into the chamber while cleaning.Keep the patch in the bore so that you do not loose suction on the water.Rinse with hot water using the same method.Dry the bore with several patches.
Dry brush the Barrel(really lets the brush get at the fouling and rust) real well and start cleaning with a good solvent like Butches Bore shine or Bore Tech Benchrest Blend.Soak the bore overnight with FP-10 clp.That usually does it for me.
If the bore is dark from pitting there is not a whole lot you can do.Other than make sure that the bore is clear of any surface rust so as to make sure it is not undersized.Then take it out and shoot a few boxes of ammo through it and clean it again.
If it shoots good an shows decent groups then your o.k.,you just have a pitted dark bore.
Ive have several k98k mausers with dark bore's that are wonderful shooters and have been for years.
They are hard to get clean after shooting and will cause a patch to shed like crazy but they are functional good shooters.
Raymond

Well, basically if it’s dark it’s going to pretty much stay that way.  There’s no way of taking pits out of a bore.

Letting the bore soak in Kroil (which is a penetrating oil) may loosen up things.

Also, this IMHO is the one and only instance where a stainless steel bore brush can actually be useful.  They are very aggressive and can damage a good bore, but if the bore is in bad shape already, they’re worth a try.  Basically they are good for scrubbing out the pits (I don’t mean removing the pits – which you can’t do - but just getting the rust out of them).

At some point, also using an abrasive such as J-B Bore Cleaner or Remington Bore Cleaner may help polish things at lest a bit.  However, they are pretty mild.

As mentioned by Blankewaffen98, a pitted bore can still be pretty accurate.  (And it’s not like Moisen Nagant’s are target rifles anyway.  [:D])

However, cleaning is going to be a chore.  I’d recommend you get some Sweets Bore Cleaner for routine decoppering – it’s quite aggressive and should speed up your cleaning.