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Primer pocket uniformity?

Started by gman47564, January 02, 2022, 07:50:02 AM

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Link to a primer article I found interesting. Towards the end it touches on seating briefly.


I read that article probably 4 years ago. I thought it was great then and still do. I didn't really understand what he meant by "the bridge" but I do now.
Someone on here mentioned primer ignition in terms of burn rate. I didn't have the time to address it then but this article brings out a important point.

Smokeless gunpowder burns, primers explode. When thinking about how a primer performs it should be in the context of brisance not burn rate.

Because ignition of the primer explosive depends on a mechanical impact rather than the presence of a flame, proper and complete ignition requires a very specific impact and an appropriate bridge. Thus, adjustment of different seating depths can result in either very poor or very optimal ignition. So once again, this is an avenue towards tuning a load.


Quote from: bikemutt on January 02, 2022, 04:04:12 PMIf the primer seating depth is more about the distance from the primer to the flash hole rather than from the case base to the primer, I wonder if single-use, or reusable shim washers would eliminate the need to measure depth, or use sophisticated primer seating tools.

Don't you just love harebrained ideas, lol :)
Chris in my quest for primers last winter I bought some #11 percussion caps for muzzleloaders. I dismantled a couple for the priming compound and they use a paper washer to hold that priming power in. It appeared to be like at him  tissue paper and when fired it would/could blow right through it but not plug the nipple on thecgun.

Maybe a paper punch on tissue wrapping paper would help you dispell your idea and provide the thickness you require to "lift" your primer. My wife said I shouldn't be shooting in the house when I was solving the ftf problem. I did shoot several primers as a test out in my mancave. My guess is it would blow right through tissue paper with enough fire to ignite powder. I would have to step out the garage for full power loads!
I've shot many times over the magneto speed after dark! She didn't like that either, she said the neighbors will think I'm nuts ( ah ye s but i am).
11X Grandfather
Part time Savagesmith


Its the "crush" of the anvil here that their trying to control if im understanding this right.. the distance between the tip of the anvil and the inside face of the primer cup.. knowen as the "bridge". I dont think you could control that with a shim..


Quote from: Rob01 on January 02, 2022, 09:47:20 AMAnd a real accuracy shooter weighs each primer separately to make sure there is the exact same amount of priming compound in each. Lol

I didn't think anyone saw me!  ;D