Regarding Flaking~

[Eugen]

As a noob, I am glad to hear some of the terms explained that I encounter in my readings. Check on the flaking thing, I've got that figured out. Well, sort of.

It took me a while to eventually figure what the heck "straw" meant. Now I've moved on to "frost in the barrel". What's dat?

[guns3545]

Originally Posted by Eugen

As a noob, I am glad to hear some of the terms explained that I encounter in my readings. Check on the flaking thing, I've got that figured out. Well, sort of.

It took me a while to eventually figure what the heck "straw" meant. Now I've moved on to "frost in the barrel". What's dat?

Eugene,

I cannot give you a metallurgical answer but I can tell you why it occurs.

In early days, i.e. prior to the 50's, all military ammunition used mercury fulminate based primers which is very corrosive. BTW, the US Armed forces were still using corrosive WWII ammunition into the early 60s.

In order to neutralize the mercury, barrels were cleaned with swabs dipped in ammonia. However the ammonia itself can cause a chemical reaction with the metal so you needed to get it out almost immediately. So, most time, you used soapy water to neutralize the ammonia and clean out the barrel.

Then, you dried and lubricated your weapon with whatever oil or lubricant was issued to you.

NOW, if you did not get out the ammonia. it caused "frosting", i.e. a light mildly corrosive film in the bore. A whitish film like the frost.

Now, frosting is not that bad. Doesn't eat away the lands and grooves like true corrosion from the mercury, but it is a sign of improper cleaning and maintenance of the weapon.

AND to Eric:

Pitting, which is severe; and freckling, i.e. tiny dots of corrosion, occurs around the muzzle, the bore itself and the breechblock, is typically caused by the action of the corrosive primer; again, when the weapon is not properly maintained. The mercury literally eats away the finish and metal if it is not removed, neutralized and lubricated. Pitting on wide spread external surfaces can also be caused by improper storage, blood and other acidic actions. As always improper care is the culprit.

WARNING!! Pitting, especially severe, unlike frosting, can cause damage to barrel, making it unsafe and be a hazard to most human beings who tend to be susceptible to coming in contact with hot flying metal particles, like exploding barrels.

Hope this helps.

John