Recently, I had cause to root through some ammunition that was stored away. It was the dribs and drabs accumulated over years, but came to a fair pile (Okay,,, it filled the living room floor...). It was ammunition from firearms I've owned and since traded or sold away. Some are hand loads built for special purposes or to demonstrate an idea, and there's some ammunition for guns I've never owned... and even I wonder where that came from. I was seeking something in particular, and found it. Along the way I found more... and it triggered questions.
Here, I picture a box of .303 British ammunition that came to me as part of a larger deal. I bought the tools and supplies of a fellow reloader who had departed the mortal world. This box was in the treasure, but I never gave it a lot of thought. I just tucked it away....
One morning I spent a few minutes looking at the cartridges and thinking. Yes, I own an Enfield #4 in .303, but these were too old for me to consider shooting. More to the point, some day a collector might enjoy these more than I.
A few of the cases were beyond collecting, due to corrosion, and I wondered what effect this had on the inside of the shell and it's load of powder. Not one to shy away from slicing up things to see how they tick, off to the bench I went! (note... they were in this condition when I got them, one reason they got stored away) I pulled the bullet using an RCBS Bullet Puller mounted in my RCBS Ammomaster press , but it did not come free easily. It was corroded to the case quite severely. That press has served me well for decades, and has the leverage and strength to utterly flatten a belted magnum case in the blink of an eye... but it still took some real effort to unseat this bullet.
Attempting to dump the powder (I was hoping for cordite strands!) I found the powder clumped and sticky. It had to be stirred with a probe to be removed from the case. Clearly it was well past usability.
I sliced the base off the case with a diamond saw running in water based lube. I'd rather not have used the water cooling on the saw, but the case had a live berdan primer and I was unwilling to be nicknamed 'One Eye' the rest of my life. I found the holes for the berdan priming system to be corroded completely shut. On top of that, the corrosion had penetrated the side of the brass cartridge and was much worse on the inside than out. Powder had caked to the case wall in the corrosion, and the inside of the case was a mass of scale. I've been tempted in the past to shoot surplus ammunition that had a few corroded spot on it, but always passed. Certainly I've seen plenty of it for sale over the years as well. Now, after seeing this for myself, I'm glad I didn't try it those times. What I found on the inside of the case was much worse than could be viewed just looking at a whole cartridge.
Sure, cleaning it up to be fired might just have meant a misfire, but it could be worse. Powder changes chemistry with time and poor storage, and brass cases can give up, leaving an unsealed chamber. Both issues are dangerous.
No, I'll pass on shooting corroded ammunition, and I'll pass on reloading cases that have spot of corrosion on them. That seems the only safe course, especially after seeing this.