Home Forums Hunting & Shooting Ask The Gunwriters Vihtavuori powder corroding brass cases

If my powder turns out to be bad when I open it, or causes any problems down the road, I won't be rewarding VV with any more of my money. But that information may be of some comfort to anyone who has some VV powder made since 2016. I'll have my camera standing by whenever I finally get around to breaking the seal on one of my N-120 canisters. If it looks good, I won't load up batches larger than I think will get used in short order. Mine has been stored inside the house all this time so environmental conditions aren't an issue.

I have to say that for you to absolutely know what happened to your cartridges, they would have to be examined.

I maintain that the powder wasn't to blame, or all of your cartridges would have corroded. I believe that a foreign substance caused the problem. The corrosion is more pronounced on the outside. My question: Were the cartridges in your initial picture completely corroded through? I am referring to the picture that you took of the outside of the cases.

I have N140, N150, N160, N540 and N550 here. All were made before 2016 and none has shown any deterioration either in their original containers, or as loaded ammunition.

One fired case showed powder residue at the corrosion site. I’d say thru and thru corrosion.

The one with the most corrosion in the photo didn’t show powder residue, empty case looked pretty good on the inside.

After a half century of reloading, I’ve never seen this.

DF

To me, it looks like contamination. For example, sweat, bore cleaner or oil. Part of their response to you was that dampness contributes to corrosion (humidity with impurities). Brass is never completely clean. Traces of what is found in reloading rooms or gun rooms - Hoppes, gun oil, Coca Cola, salt, etc. - find their way onto metal surfaces. For example, you eat some potato chips, or have a bologna sandwich for lunch and don't wash your hands. Traces of your lunch deposit themselves on the brass and bullets. They react with moisture and the deterioration begins. To me, the majority of the corrosion appears on the outside of the cases, with far less on the inside, located at the heel of the seated bullet. This could have resulted from contamination from your fingers,transferred when you placed the bullet onto the case mouth and seating it. Or when the bullets were loose on the table, waiting to be seated.

Deterioration is accelerated by changing humidity in storage. Varying temperature is usually responsible as well. In your case, contamination would be my first check because you said that the temperature and humidity were constant. The reaction is slower in a controlled environment. That is, little variance in humidity or temperature.

If the propellant was the actual cause, then it's reasonable to expect that all the cartridges would shows signs of corrosion.

In the end, you would have to send it to a lab to determine the exact cause. At this stage, it's just a guessing game.

I am telling you it's boogers.

It's snot what you think.

It could be!

Hmmm...

Guess I’m caught, red handed. Didn’t think anyone was watching.

Ha!

DF

DIRT FARMER,
In my opinion Steve Redgwell has this issue nailed. I have also been in contact with BRISTECD via company email on this regarding his .223 loads. What you both have in common is that both of you live in areas of the country known for very high humidity and temps. Both of you have stored your ammunition in plastic cartridge cases . Because these cartridge cases are not sealed. Even though you both have AC there is enough moisture in the air to start the corrosion process. Both of you have also said that this ammunition has sat loaded for 5 to 6 years at least. My advice is that IF you are going to store ANY loaded ammunition for any amount of time where you live. That you use GI ammo cans with GOOD SEALS on them to help with this issue. I do . And I have not had any issues with ammunition corrosion issues like this. BUT I always check the cartridges occasionally to see if any issues are starting. Also I advise that you strip this ammunition that shows corrosion. Don't shoot it. No ammunition , even military ammunition the has both the bullet and the primer sealed can be stored indefinitely . M14 and FIRING LINE websites have a great string on the life of ammunition. The information from LAPUA and VIHTAVOURI I sent you also speaks to this I believe.

Take care,

Philip Hoham
Technical Support
Capstone Precision Group, LLC

24732 Randall Rd. | Sedalia, MO 65301
Tel: 660-460-2802
AS WITH ALL RELOADING, APPROACH THE MAXIMUM LOADS WITH CAUTION, AS ALL RIFLES AND RELOADING
TECHNIQUES WILL BE DIFFERENT. IF YOU CHANGE ANY OF YOUR COMPONENTS: THIS INCLUDES DIFFERENT POWDER LOT NUMBERS; YOU MUST REFIGURE YOUR LOADS BY STARTING WITH THE MINIMUM LOAD.

Philip,

Welcome to the Campfire.

You’re an important technical information resource and we appreciate your time and input.

Thanks,

DF

Now you know not to pick your nose while reloading.

Old habits are hard to break...

You know, old dogs, new tricks, etc, etc.

Ha!

DF