I have about 75 rounds of primed 50BMG brass that I am going to make dummy rounds from. The brass was all FL sized and primed before it was found it would not chamber in my gun. It was fired in a friends 50 rifle. His rifle has a sloppy chamber that allows the brass to expand about .005 right at the head. That bulge cannot be taken out by my dies as that portion of brass is too low to be sized. I have pushed out a few of the primers with my sizing die, but chickened out after a while. If you have ever heard one of these go off in the open it would scare the heck outta' you. I designed this 3/4" pipe popper. With the help of my gunsmith, he drilled the pipe cap and machined a firing pin from a bolt to mount in it. Put the brass in the pipe, screw on the cap, drop the whole thing onto a 3/8" steel rod that is stuck in the ground, then whack it with a hammer. Most of the primer is blown out under the cap and the gasses are vented down, mostly on the outside of the brass and out the bottom. The outside of the brass is blackened with primer residue, but that will clean up. I also droop an old T shirt over the whole thing before popping it. The explosion is "surpressed" and made into a mouse pop.