4x4 - Home


Primer Pocket Swaging

Most military brass has crimped primer pockets.  A very thin lip of brass is folded against the edge of the primer to secure it in place.  When military brass, such as 5.56 x 39, is reloaded for use in a personal firearm, that brass lip around the primer pocket must be dealt with.  There are two commonly used methods, swaging and reaming.  I've not used the reaming method and don't really care to since I've had good results for many years using the swaging method.  This write-up will detail one of the swaging tools that are available, the RCBS Primer Pocket Swager.


The RCBS Primer Pocket Swager, let's call it the swager for now, is comprised of the components shown above.  It is designed to swage both large and small primer pockets.  This means you can handle military crimped brass such as .308 (large primer) and .223 (small primer).  A small swager rod is included that is used specifically for .223 brass.  All other calibers use the standard rod.


The body is screwed into a standard 7/8"x14 threaded reloading press.  Instead of a conventional shell holder, the large or small swager head is inserted into the ram on the press.  Since I'm using .223 brass, I snapped the small head into the ram.  The case stripper is positioned over the top of the head so that the head protrudes through the stripper.

The swager rod must be backed up snugly against the body in order to avoid damage to the rod.  Be sure the lock ring on top of the body is kept tight.  The amount of primer pocket swage is controlled by moving the body in the press, not by adjusting the position of the rod in the body.


To use the swager, place the mouth of the brass over the swager rod and lower the handle on the press (raising the ram).  Screw the body downward until it contacts the web of the case.  The web is the brass at the bottom of the case interior.  Raise the press handle and screw the body into the press about another 1/4 turn and lock the ring into place.


The ram is raised again (since the quarter turn adjustment was made) and then lowered.  The brass case will most likely be stuck on the end of the head.  By fully retracting the ram, the case stripper will push the brass off of the head. 

At this point, one can test the primer pocket by priming the case.  I have found that even when properly swaged, it takes a little more effort to prime swaged military brass compared to regular brass.  Once the brass as gone through the swager, there is no need to do it again.  It is a one time operation for your crimped military brass. 

You may need to adjust the depth of the body a little bit more.  Also note that different lots of brass (different head stamps) can have slightly different dimensional differences in the webbing and so the proper swage for one lot may not be optimal for another.  Sorting your brass into lots prior to swaging allows you to easily make a quick adjustment should you need to as you move from one lot to another.

I've had this swager for about 30 years.  I originally used it on a smaller Lyman single stage press and because of that, I had to cut away a portion of the case stripper so that it would fit.  Needless to say, I have gotten my money's worth out of it.  It still carries the price tag of $12.50.  I've not looked up the price to see what it currently sells for, but I'll bet it has doubled or more by now.





4x4 Off-Road    Homestead    Firearms    RC Flying