Thread: How to Tell if Ammo is Corrosive
08-29-2010, 01:51 AM #1
- Join Date
- Oct 2009
- The Hoodlands
How to Tell if Ammo is Corrosive
I have heard that the old military surplus corrosive ammo has primers that are round, while the non-corrosive stuff has flat primers like you would find on American non-corrosive ammo. Has anyone heard of this? I bought a spam can of 5.45 and it's supposedly corrosive but the primers are as flat as any other centerfire cartridge I have.
ETA: I compared the 5.45 to some surplus 7.62x39 and the 7.62 does have round primers.
08-29-2010, 03:31 PM #2
For American ammo, the date of manufacture is the means of determination and can be looked up. For foreign stuff - well, you kinda take your chances.
The material used in the primers changed from (corrosive) mercuric fulminate to (noncorrosive) lead azide. The design (and therefore shape) of the primers did not change.
You can use corrosive primed ammo, but you have to be pretty religious about cleaning after firing.
08-29-2010, 04:11 PM #3
- Join Date
- Nov 2008
I heards of a way to figure out if they are corrosive. Pull a bullet and powder (with any kinetic bullet puller). Load the round into a gun, and point it at a piece of steel (in a safe direction, of course. I'm pretty sure it is steel, but I could be wrong). Clean the gun as if it is corrosive ammo. If it is corrosive, it will rust the steel pretty quickly.Do not pray for easy lives. Pray to be stronger men.
08-29-2010, 05:14 PM #4
08-29-2010, 09:55 PM #5
08-29-2010, 10:05 PM #6
08-29-2010, 10:13 PM #7
It's OK to FIRE corrosive primed ammo. What happens is that the mercury compounds for corrosive salts that are hygroscopic (attract water). If you leave the barrel dirty, it will corrode quickly - much like it would if you exposed the barrel to salt water. Mercury itself doesn't damage steel. Gunsmiths used to use mercury to dissolve bullets stuck in muzzleloaders. It's the corrosive salts that cause the problem. If you clean the barrel after every use, you'll be OK.
Mercury does attack and quickly weaken gold, silver, lead, aluminum, copper, or brass. So it's not good to have it around ammo or guns with nice inlays.
08-30-2010, 05:35 PM #8
08-30-2010, 06:44 PM #9
- Join Date
- Aug 2010
- The great country of West Texas
08-30-2010, 11:59 PM #10
I've seen some posts about using ammonia cleaners (like window cleaner) to scrub your gun. That's pretty much unnecessary. (Although the ammonia will help get rid of copper deposits.) The idea is that the mercury salts are soluble in water and the ammonia is supposed to reduce the acidity. If you clean the gun like you should, you'll get the salts out. After all, up until the late 1950's, ALL ammunition used corrosive primers! People who took care of their guns didn't have problems.