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Getting Started Reloading .223 Rifle: Crimped Primer Pockets

Filed in Articles, Case Prep, Reloading .223 Rifle Ammo by on April 3, 2014 0 Comments • views: 3773

crimped primer pocketsIf you have meed reloading pistol calibers for a while and are about to start reloading .223 rifle ammunition then this article is for you. It is one in a series of articles on this topic.

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.

The drawing above is from the SAAMI (Sporting Arms and Ammunition Manufacturers Institute) specification for primer pockets. The drawing is a little blurry but you can see that the minimum diameter of the small rifle primer pocket should be .1730 inches and the maximum is .1745 inches.

Crimped Primer PocketI grabbed a random .223 case from my pile of military surplus .223 brass and measured the primer pocket. You can see from the photo that it is .169 inches, significantly smaller than the minimum specified by SAAMI.

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.

(I still remember the day I did this for the first time.  I call it “The day that Dave discovered crimped primer pockets.)

What To Do About Crimped Primer Pockets

There are three things we can do with crimped primer pockets:

  1. Cut the excess brass away to return the pocket to it’s original diameter.
  2. Swage the pocket, pushing the crimp back out of the way
  3. Throw the brass away, sell it for scrap or give it to someone else.  (Probably not the best choice.)

Primer Pocket Reamers

primer pocket reamerI tried primer pocket reamers.  In fact I purchased the Lyman Primer Pocket Reamer shown here. Of the reamers I tried, I liked the Lyman the best due to the ergonomic shape of its handle.

The only downside of one of these devices is that using it to ream thousands of primer pockets would be tedious and take forever. (At the time I had approximately 4000 rounds of milsurp 223 brass to process.)

Primer Pocket Swages

rcbsprimerpocketswageThere are several swaging devices available.  I purchased this RCBS Primer Pocket Swaging kit. It is designed to fit in a single-stage reloading press and provides a higher-volume solution for processing primer pockets. I can attest to the fact that I could swage brass with this device faster that reaming them using any of the hand reamers I used.  The downside is that I kept smashing my thumb from not getting it out of the way quickly enough.

What I should Have Bought In The First Place:

Super_Swage_600_mI 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.

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