Base punch and primer pocket

[BT Sniper]

Hey guys got some thoughts and observations reguarding using cartridge brass for jackets.

I have modified my base punch for the core seating dies so as to seat the core verticaly or upside down. I weigh my cores and brass so I'm not looking to squezz any excess lead from the core. What I have noticed is I get less lead flowing around the poor seal of the punch when I seat the core verticaly but my problum is the extraction grove dosn't always compress evenly causing a slight runout on the base of the bullet. If I seat the core upside down as supposed to I get no run out of the base of the bullet but do get some lead flowing by the edges. I know.. i need a tighter tolerance core seating punch.

But this got me to thinking, For those of us that use cartridge brass for jackets what if a punch was made to fit the inside of the primmer pocket as well as supporting the rest of the rim? This would seem to ensure that the cartridge would be centered. I would be seating the core verticaly.

Just some more thoughts from a simple mind. I'll give it a try and see what happens.

[BT Sniper]

While on the topic of primer pockets anyone have any thoughts as to the difference between shooting cartridge bullets with vs. without the spent primer still in place. I know the weight difference is 3 grains and I suppose it would create more room for an extra grain or two of powder on compressed loads but what effect do you supose the pressure would have on the open end of a bullet with an empty primmer pocket?

[kawalekm]

Hi BT

I suspect that if you have lead leaking around the punch, then maybe the core is not being pressed far enough inside the die. I haven't checked, but I would suspect that CH dies have a slight amount of taper to get core started. Perhaps if you screwed the die body down into the press a few turns you'd raise the core seating area past the taper (if there is taper).

I think that not extruding any lead at all is a mistake. I believe that adding enough pressure to extrude even a little tail out of the core will result in more consistant swaging than if you just seat with enough pressure form it out. Perhaps if you swage the core with enough pressure to get extrusion, then the variability with your extraction grooves would disappear. I know doing this is tough. I've already broken one press frame by applying too much pressure. Now, what I do is apply as much force as I can with one hand only, and wait till I can feel a bit of lead extruding. If you do this slowwwwly you can actually feel it when you've reached extrusion pressure. After getting the die adjusted just right, I can slowly raise the pressure up to the extrusion level, just as the press "cams over" where I leave it for another 5 seconds. That I think will give you the very best cores.

I've made bullets with cases both with and without the primer in place. What I've seen is that the lead will extrude out the primer hole just like it does the core seating hole. It comes out as a short peg as long as the primer is deep. I've never see a primer pocket though that was full of lead. Once the peg reaches the bunch it just stops and acts like a pillor supporting the rest of the lead.
Michael