Dumb question

[clovishound]

Before I changed how I picked up my brass to put in the press, I occasionally had a .357 mixed up with .38, or visa versa. I always just moved the turret around to the decapping station, pushed up on the primer cup, and carefully pressed the primer out of the case. Never had an issue. Not saying they couldn't go off, but it would only be one, and they don't have that much power, especially since there should be plenty of room around the decapping pin for gases to escape.

[Mags]

I've shot some cap only reloaded cases. Sounds just like an old toy cap gun but a little louder.

[Bubbas4570]

I have also removed many live primers from cases. Never had one go off, and I don't for the life of me understand how there would be the ceiling damage done that I have heard about....if your dies are set up correctly there would be just as much if not more steel wrapped around that case head is there is in a firearm. And a primer is not really that big of an explosion in my mind. Yes it's loud, but nothing much more than startling. I also recommend using penetrating oil of some sort to deaden the primer if you have any concerns with detonation, and brake cleaner or something of such sort to clean the case before proceeding on.

[clovishound]

I believe the ceiling damage folks refer to is from progressive presses that use a primer tube. This is a tube that is filled with primers and feeds the primer seating mechanism. As I understand the issue, sometimes a primer goes off in the press and sets off a chain detonation in the primers in the tube shooting exploding primers out the top of the tube, and often bursting the tube.

It is not an everyday occurrence, but happens often enough that you will see the occasional post about it on reloading forums, and there will be a fair number of folks who chime in and say the same thing has happened to them at sometime in the past. Both Hornady and Dillon use the tube system, but the reports of mass detonation are normally involving Dillon. It might be that there are just lots more Dillon presses out there, or it may, as I suspect, have to do with the design of the mechanism Dillon uses to move the primers from the tube to the seating device.

[Bubbas4570]

I know all of the manufacturers design their primer handling systems to keep detonation for occurring, but it IS mechanical.....
.....and there are humans involved. Things happen.

I am going to surmise that many of the detonation occurrences could be traced back to ignition of a primer, flame igniting loose priming compound, and trailing into primer tube/tray for mass ignition. I know how far the primers are moved in the loading sequence.....that is a LONG flame to get I to primer stack.