I do not use compressed loads, but I was thinking of the possibility of causing an accidental discharge caused by pressured through primer hole against the anvil inside the primer especially with spherical powder, imagine the results

No, that can't and won't happen.

My guess is that if by some way the powder was forced through the flash hole with sufficient force to do anything, it would push the primer out of the pocket instead of pushing the anvil into the primer case.

Consider that black powder was originally, and I do now, compressed routinely 1/4 of an inch; far more than any smokeless powder. That doesn't force any powder through the flash hole. Your brass case would bulge first before any powder at the flash hole had any pressure on it.

To fire a primer it must be struck hard enough to shatter. You can press out a live primer with a decapping pin and reuse it.

quote:

Originally posted by Ray B:
My guess is that if by some way the powder was forced through the flash hole with sufficient force to do anything, it would push the primer out of the pocket instead of pushing the anvil into the primer case.

I've done this with 5020. roger

I would have never guessed.

quote:

Originally posted by raamw:
I do not use compressed loads, but I was thinking of the possibility of causing an accidental discharge caused by pressured through primer hole against the anvil inside the primer especially with spherical powder, imagine the results

Doesn't and would never happen.
An example, 375 Weatherby with W760 and a Woodleigh 300gr over 90gr of powder, discovered this was too hot in the heat of summer here. Pulled the bullets to adjust the charge, the powder was so compact, I had to dig out the powder with an awl. It had gone solid.
I think it was hornady, they fired 50BMG into a pallet of loaded ammo, only those cases that were hit on the primer directly detonated.
A bullet strike is far more compression than seating a bullet over powder.

Cheers.

Compressed loads as a rule are your most accurate loads..YOu can compress up to 110% or more, but I usually don't go beyond 107 or 108 with some powders that allow it as it may overnight push your bullets forward..H4831 does this on some guns with tight chambers, you could never get enough of some powders such as H4831 in a 30-06 case to cause you problems for instance as pressure as so low to start with.

What kicks primers out is high pressure and if you put too much of some powders in a case it will blow a primer or blow up a gun, for instances a fast burning powders like bullseye will destroy a gun pronto with just a few grains, and most blow up are just that sort of mistake on the shooters part. remember the primer is backed up against the bolt face, and it takes some kind of headspace to allow the primer to go anywhere.