SVT bores.. and a definition of 'frosted', pitted, etc.

manbearpig

manbearpig

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im looking at a 1941 arsenal refurb Tula SVT-40, and the bore appears shiny with strong rifling but the entire thing has a faint roughness along it. rather than pockmarked 'pitting' its more like a faint orangepeel effect along the metal.
is this from rough tooling? or is it pitting? how does this affect the value of the rifle?

i know how to evaluate the condition of the chamber and bore of a modern production rifle, but my experience with milsurp bores is very limited. you cant always trust gunsmiths for a definition, because theyll just glance down the barrel and say 'yeah it looks OK' or something equally vague. most gun dealers/gunsmiths ive personally encountered will gloss over the condition of rifles they are trying to sell, and piss all over a rifle you want to buy from someone else that you ask them to look at because they want to sell their own stock... or theyre just too busy to give it more than a cursory glance.

ill try and take a photo of this particular barrel later tonight, but in the meantime is there a more clear definition of 'pitting', 'frosting', 'shiny', etc? can a barrel be both pitted and shiny? are pits that people commonly refer to only the rough pockmarks in metal, or is a faint roughness in the metal also considered pitting? how dark is a dark bore?
when someone refers to a milsurp as having an 'excellent shiny bore with strong rifling' does this mean the bore is glass smooth like current factory rifles or is this description relative to other old milsurps and the bore is not glass smooth?

ive done my best to research this before posting - ive spent hours scouring the net for a site that has photos of examples of different milsurp bore conditions but it seems that any photos of bores are super rare. sites just have vague descriptions such as 'check to see that the bore is shiny', which doesnt help me much.

thanks in advance for any help.
 
As far as I am concerned, the "strong rifling" term is meaningless. I have seen strong rifling in barrels that were black and rough from one end to another. Frosting, faint roughness, etc. are just varying degrees of corrosion damage. Corrosion damage could range from slight etching to heavy scab rust. Yes, a bore can be shiney with pits. It can still have some shine even though there may be pitting from end to end. Apart from corrosion damage, there is bore deterioration from use, normal wear and tear. This usually appears first in the leade or throat of the bore, and progresses down the bore as more rounds are fired. Cordite is particularly erosive. There can also be damage from improper cleaning, particularly with a pullthrough; this usually occurs at the muzzle.
Often it is difficult to accurately assess bore condition, because the barrel is so fouled that the surface cannot be observed. Metal fouling in particular can be difficult to remove.
 
i may not be 100% correct but as far as i know primers are usually the corrosive component in corrosive ammo. corrosive primers leave salts in the barrel which need to be neutralized with cleaning solution, hot/boiling water or ammonnia or they will quickly rust a bore within hours of firing.

i guess we shouldnt be too suprised that so many milsurp rifles have bad bores, since many of the soldiers using them were just peasants and firing a single round of corrosive ammo through a rifle and not cleaning it is enough to destroy a bore. even though caring for your weapon is drilled into you in the military, im sure there were many times when they had a lot more pressing issues to worry about than promptly cleaning their rifle.

cleaning something like a mosin after firing corrosive ammo isnt so bad... cleaning an SVT after firing corrosive is a HUGE PITA since you have to take the entire rifle apart and clean everything. no wonder they werent well received by the russian troops.
 
'Frosting' is the beginnings of erosion. Looks just like the frost on your pumpkin. It doesn't come out with normal cleaning.
Pitting is the result of rusting. The steel is eaten away in that spot. Remove the cause of the rust and it stops. The pitting doesn't go away though as the metal is gone.
"...What makes cordite so erosive?..." The chemical composition of the sticks. Cordite looks just like spaghetti. It's part guncotton(cotton soaked in nitric and sulfuric acids), part nitroglycerin and part vaseline. As I recall, it burns hotter than modern powders that are made by dissolving guncotton in ether and alcohol. Hatcher's Notebook has a whole chapter on gun powder.
 
sunray said:
'Frosting' is the beginnings of erosion. Looks just like the frost on your pumpkin. It doesn't come out with normal cleaning.
Pitting is the result of rusting. The steel is eaten away in that spot. Remove the cause of the rust and it stops. The pitting doesn't go away though as the metal is gone.
"...What makes cordite so erosive?..." The chemical composition of the sticks. Cordite looks just like spaghetti. It's part guncotton(cotton soaked in nitric and sulfuric acids), part nitroglycerin and part vaseline. As I recall, it burns hotter than modern powders that are made by dissolving guncotton in ether and alcohol. Hatcher's Notebook has a whole chapter on gun powder.
Click to expand...


Interesting. I've got a bunch of cordite loaded .303 British that I was going to shoot. Maybe I won't...

Hatcher's Notebook is in my shopping cart at Amazon :) Just need to add a few more books to get free shipping!
 
depends on what you shoot it in. i wouldnt hesitate to shoot corrosive in an old bolt action like a mosin - over a day at the range youll save a lot of money. just give the bore a quick clean at the range and then a thorough cleaning when you get home.

a semi-automatic like the SVT though, ill never shoot corrosive through again. such a huge PITA to clean afterwards, many people think that the corrosive ammo just needs to be cleaned from the bore but it actually requires a complete strip and thorough cleaning of the entire rifle since it gets all in the gas system etc.
 
manbearpig said:
a semi-automatic like the SVT though, ill never shoot corrosive through again. such a huge PITA to clean afterwards, many people think that the corrosive ammo just needs to be cleaned from the bore but it actually requires a complete strip and thorough cleaning of the entire rifle since it gets all in the gas system etc.
Click to expand...

You most definitely speak the truth! Exactly why I shoot my mosin the most! Cheap ammo and easy to clean.
 
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