Primer Pockets

[D.Hayden]

From another post about brass, people mentioned different ways of dealing with the primer pcokets on some brass (most notably S&, and listed Ream, Swage, Deburr (and variations) as methods of 'fixing' the primer hole. Can someone explain to a begginer what these are, and how they affect the round?

[kevin c]

Reaming primer pockets is, from my understanding, mainly done to square the base of the pocket to insure the most uniform and consistent primer seating, and supposedly, therefore, the most uniform/consistent primer ignition. A hand held or machine mounted cutter scrapes the bottom of the pocket. This is not to be confused with primer pocket cleaning brushes, which mainly scrape out deposits of primer residue, and don't remove much metal. I think that this is mainly a bench rest kink without much practical application to action pistol. Ditto flash hole uniformers, which are supposed to make the flash hole more truly round.

Swaging refers to reforming metal by forcing it through a die or form. Most commercial lead bullets are swaged rather than cast, for instance. Brass can be swaged too, and when a piece of military or commercial nontoxic brass is decapped, the rim of crimped brass left around the edge of the primer pocket (which makes it difficult to reprime the case) can be removed by a swaging device which can be bought from different reloading manufacturers (Dillon supplies a swaging station on their high end 1050). Some people do refer to this process as reaming.

Deburring is the removal of the tiny rough tags of metal left on the surfaces of a finished piece of metal after cutting, swaging, drilling, etc. As far as reloading goes, it mostly applies to cleaning up the case mouth after case trimming, though maybe this applies to primer pocket swaging as well (don't know, since I just chuck military and NT cases when I find them - the hassle factor of doing all the above just for a few cases is way too high for me)

[TBF]

Barkim,

Swaging uses pressure to force brass into shape. Generally a dedicated bench mount press.

Reaming/ deburring cuts metal from around the primer hole to remove the offending edge that makes primers difficult to seat.

Swaging tools cost alot more than cutting tools.

Unless you have a whole bunch of brass to do, and a lot of spare time, just chuck the uncooperative brass and spend more time shooting.

Benchresters use pocket uniformers to equalize the depth of the primer pocket, but they also can easily tell the difference between loads that shoot 1/4" better at 100 yards.

Travis F.

[JFD]

Lyman (probably others as well) sells reaming tools to cut the crimp out. Fairly easy, but you'd want to swage the crimp out if you're dealing with more than a handful of cases. You can also use your deburring tool to ream the crimp out. It works just as easy as the Lyman tool, but doesn't touch the rest of the primer pocket.

I've never noticed any difference between the 3 methods as far as case life goes.