I was recently reloading some mixed cases of 45acp and noticed that the speer cases had a bigger flash hole than the others. I found that win,fed,rem have what appear to be the same size. Will this make a difference in the reloads? I'm only making plinking rounds but wondered if I should be more careful with the speer brass when approaching max loads

I would imagine that a larger flash hole will alter the burn characteristics of a cartridge, all else being equal.

For modest loads (plinking), mixing case brands is probably OK, but it is prudent to develop maximum loads with a specific brand of case, and stick with it. In fact, if ANY component changes, back the powder charge off by 10-15% and work up again.

In theory, maybe, it might make some slight difference. But, primers are designed to shoot out a narrow stream of ignited powder through a small hole. That narrow stream of fire is much smaller than the smallest primer hole thereby having little or no effect on the load. Jim

Whew! I'm glad we cleared that up. I was worried there for a second...

Wnchester makes a "non-toxic" ammo for indoor use that has a large primer flash hole. I don`t know if Speer is following suit but could be. The stuff of Winchesters is supose to be fine to load, the same as regular brass.
Sorry I can`t be of help.

quote:

Originally posted by Jim Kammerer:
... That narrow stream of fire is much smaller than the smallest primer hole ...

Hey Jim, Could you expound on that a bit?

Either you know something about the Primer Dynamics I don't know, I misunderstood what you are saying, or you are full of beans.

Of the three options I'll pick the third one.

The flash hole acts much the same as a carbuerator jet in old automotive carbuerators. Alter the size and you'll alter the load. Alter it enough and you could have gun parts in your body.