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Crimped Primer Pockets

Filed in Articles, Case Prep by on June 26, 2011 0 Comments • views: 1352

Crimped Primer PocketIf you are new to reloading 223, 308 or other calibers using my the military then you need to know about crimped primer pockets.

My personal story: I reloaded 45 ACP for many years and had never heard of crimped primer pockets.  When I started reloading 223 I thought I already knew what I needed to know about reloading it. Boy was I wrong.  I had acquired some military surplus once-fired brass.  SUddenly I found that the primers wouldn’t go into the cases. I was applying a lot of pressure to the arm of the press and the primer just wasn’t seating.  “Something is wrong”, I said.

At first, I thought something was wrong with the newly-purchased used press. Nope. I still remember the moment a few evenings later when I found the primer pocket dimensions online and measured one of my cases with a caliper. The diameter of the pocket was too small. A little more time spent online and this is what I discovered:

Ammunition produced by factories that make ammunition intended for the military has crimped primers.  The reasoning is that the high vibration of a fully automatic weapon will occassionally cause a primer to back out of the pocket and jam the gun.  In combat that is a Very Bad Thing. Therefor the primers are crimped in place to prevent that.

In the photo the crimp is the small circular indentation around the primer. While the normal de-priming process will have no problem getting the old primer out past the crimp, it’s impossible to get the new primer in without first removing the crimp.

I’m going to cut right to the chase and tell you that if you have more than a very small number of cases that are crimped then spend the $110 and but the Dillon Super Swage 600.

I tried to cheap out:

  • I tried cutting the crimp out using my RCBS debur/chamfer tool. It worked but it was SOOOO slow. There is no way I could process a thousand cases that way.
  • I tried the RCBS Primer Pocket Swager Combo ($38).  It worked, slowly, and it was a pain.  I lost track of the time I smashed my thumb because I didn’t get it out of the way in time.
  • I tried various hand tools that you shove into the primer pocket and twist.  The worst of them wore out after a few hundred cases. The best of them were WAY to slow to ever consider for doing a thousand cases.

I finally broke down and bought the Dillon Super Swage 600. It was a night-and-day difference.Effortless to use and fast. The only drawback is that you need to sort your brass before using it.  EVery manufacturer makes their brass to slightly different internal dimensions. Sometimes that web thickness dimension will vary between two different lots from the same manufacturer. Frankly, that’s a small price to pay.

I didn’t time how long it took me to swage a thousand cases but it was not long at all.

In retrospect, if I had taken the money I spent on ‘cheaper’ solutions I could have paid for the Dillon Super Swage in the first place. Don’t make that same mistake.

Here is a YouTube video showing the Dillon Super Swage 600 in action.



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