tickfarm
It doesn't look like it in the pic, but that .45 case spent the last 20-odd years in a friends leaky old barn. My guess is that the corrosion that was all over the surface before I cleaned it moved down into the interstices between the case and primer. The resulting oxidation caused the metal to "weld" together.
(An hour later...)
Well, that guess was WRONG!
I decided to try and come up with a way to remove those "primer walls" and help you get those cases into usable condition while also satisfying my curiosity as to why this particular .45 primer came apart, while over 800 others, stored under the same conditions, didn't.
I decided to try the punch that I use for decapping really stubborn Berdan primers. First I ran a die (in this case a .308 trim die, but anything that the case will fit tightly into will work, but DON'T USE A CARBIDE SIZING DIE) into the press from the bottom of the threaded portion up until it protrudes from the top of the press.
Then push the case mouth into the die so that it fits tightly and use a small hammer to drive the tip of your punch into the inside of the primer wall. You don't want to put it in so far that you go through the primer wall and into the side of the primer pocket, cause then you're likely to get gas leakage that'll trash your bolt face.
After you've got a good "bite" in the primer, use your hammer to tap down on the side of your punch using the case head as a fulcrum to lift one side of the primer out.
Once it starts to move, the job is essentially done and the primer will pop out easily.
The best way I've found for removing the case that's now jammed in the die is to use a 4 inch deck screw with the point rounded off and the head ground to fit a .223 shellholder. Just push down on the handle of the press and the screw pushes the case out easily.
Since I can usually decap about three Aussie Footscray (the most heavily crimped primers I've ever encountered) 7.62x51 Berdan primers a minute, you can probably do 6 or even 8 of your .30 Carbine primer "doughnuts" per minute once you get the hang of it. It literally took two light taps on the head of the punch and two on the side and it was done (at least it woulda been if I hadn't been trying to get pics)
Once I got it removed, looking at the outside wall of the primer "doughnut" made me pretty much give up on the idea of "corrosion welding" as the cause of this problem since the nickel plating is as smooth as a baby's behind and the walls of the primer pocket are no worse than the pockets that deprimed normally.
I now have absolutely no idea why this particular primer came apart like that and none of the other 800 odd primers did, especially when you consider that a couple hundred of 'em were over 50 years old, not nickel plated AND were crimped in!
Does anyone out there have a better theory than my original "corrosion welding"?
Don't you just hate it when a beautiful theory like that gets mugged and beaten to death by a gang of facts!
There are a lot of cases that I wouldn't consider being worth the effort to salvage, but I think .30 Carbine is probably worth it. I know that I don't find 'em laying around very often on the ranges I go to.
If you run into any problems or need help on exactly how to grind the punch, feel free to shoot me a PM and I'll try to talk you through it.
I'd advise against trying to drive anything between the primer and case, it doesn't take much of a scratch to allow blow by when you've got 40 thousand PSI trying to find its way out.
And seriously, unless you've successfully used CCI #41's in your Carbine previously, try a more easily ignited primer or the question in your next thread is gonna be "Is it safe to decap live primers?"
