If you want to reload once fired L.C. 7.62x51mm brass on a progressive, in addition to normal brass preparation, the crimp in the primer pocket has to be dealt with in such a way that there's no chance of a primer being mangled as you pump out the rounds at speed.  Hickups in the primer seating process, is the rule not the exception, unless you eliminate Murphy from the equation.

I bought an RCBS swager 35 years ago, to use on some 1000 rounds of 1968 LC brass.  At the time, I was necking it down to .243.  I lost interest in that project, when it proved to be more pain than fun, partly because I couldn't depend on the swager to do its job.  So now, I want to just reload the stuff for my DPMS .308, on my RCBS Pro 2000, but I found that it didn't remove enough of the crimp, when I swaged it all in one big batch.  So, I bought a new version the the same swager, the Combo version, with parts for small primer pockets also. (for .223.)  I figured that I must have had an out of spec button on the old one, and surely the new one would be in spec.  Not a chance...it didn't work any better.

SAMMI specifications for primer pockets are .2085" -.2100".  My old buttons (I had 2) were both .207".  The newer combo kit's button measured .208" still under spec.
So I emailed RCBS and eventually got to communicate directly with a R&D engineer.  I sent him my new combo unit and all 3 of my buttons.  His answer was this:


The two new buttons he sent measured .210" and finally I can make it work!  Here's the process I have to go through.

Mount the button to the ram, and put the cup over the button.  (the cup forces the brass off the button when you return the ram.  You have to bang it)

The tool is ready to use once you screw the body down far enough, that it will press the button all the way to its hilt.

The arrow is pointed to the "hilt" past the rounded fillet.  The point is, for the primer to go in easily the edge of the pocket has to be rounded. Like the picture below.

The case on the left is swaged.  Notice the rounded edge.  To get that edge the ram has to over cam a bit.  (Too much and the rod bends)  Notice the bright line just inside the round-off.  That is a super thin sheared ring of brass that has to come out one of two ways.  Either by light scaping by an exacto knife, or by running the pocket into a pocket uniformer. (I wanted to uniform the pockets anyway.  Two birds...) Next picture shows the sheared brass.

I found out that if you don't get that out first, the primer will seat high and forcing it in will crush the primer a bit.

This is what I mean by pressing the button in to the "hilt"  Plan on some good light and you need good eyes to see this on the press with the cup over the button.  BTW, what you're looking at, is not a pleasant experience. (swaged brass on button...forgetting to mount the cup first...it will happen to you...more than once.  For the picture I did it on purpose, but that's because I figured out a way to get it off easily without damaging the brass.  I'll demo that with a picture or two at the end.

Here I'm using the RCBS Trim Mate to uniform the primer pockets.  Besides getting rid of the sheared ring, uniforming the brass makes it possible on my RCBS Pro 2000 to make each and every primer seat exactly .007" deep, because the press has a primer stop that stops the ram at the same spot every time.  That wouldn't be worth much, if the primer pockets were at various depths, which they are, until "uniformed."

Notice I use a rubber "band" to hold the brass while I use the Primer Pocket Uniformer in the Trim Mate.  Makes it so much easier because the brass doesn't slip in your hand.  I cut off a 5" piece from a small Craftsman bottle opener.  The opener works just fine without the 5" piece.

Anyway, once uniformed, the primer pockets are primed easily, even in the progressive.  The uniformed holes guarantees that it'll work in the press because the brass will not go into the "uniformer" unless the swage is good enough...found that out with all the undersized buttons.

If your swager button on your tool is undersized, expect Murphy to screw up your swaging plans.  You will have mangled and/or deformed primers.  Measure them with calipers at the point just off of the rounded fillet.  If they measure less than .010" call RCBS and tell them that you want a button that will work.

Now for how to pull a case off a button where you forgot to add the cup to the tool.

Find a washer that will go over the button, but has a small enough hole to cover the case head.  The use a reinforced Dremel cut-off wheel to cut a slot so you can put the washer on.

This washer is going to save the case head from damage during the operation.

Just mount the button in a vice and use two smallish flat headed screwdrivers on each side under the washer and twist the screwdrivers under the washer.  The brass will pop out undamaged.

Now those who are wondering whether the RCBS Swager works, knows the answer.  BTW, the small pocket version worked fine out of the box.
I don't know anything about the Dillon Swager.  Maybe it works better.  I've read where it can be adjusted to make the pockets TOO big, and that wouldn't be so cool.  On the other hand if the things adjust that far, a little experimentation, might make SURE the pockets are not too small.

I read where a Dillon user uses RCBS buttons as a gauge.  Based on what you read here, I would, only if you're lucky enough to get the .210" button.  I may yet buy and try the Dillon tool.  We'll see.  Depends if I shoot the hell out of my .308's enough to buy a million more cases.

Oh!  BTW, I did try RCBS's Trim mate Military Crimp Remover Cutter, too!  It does work if the huge-looking chamfer doesn't scare you.  Either way the RCBS Pro 2000 seated the primers easily at exactly, .007" deep.  Here's a picture showing a sample of each primed.  I don't know if there's a legitimate reason to be spooked by that much brass taken off or not.  The looks are deceiving, it really isn't deeper than .007"!  Both are seated identically depth-wise!

I've owned a Dillon swager for thirty years.  It swages 7.62 mm with no trouble, as well as 5.56mm swager attachment.  Very fast.  Since I load for accuracy for my SuperMatch, I use a RockChucker and INSPECT, INSPECT and INSPECT.  My primers are loaded smoothly and evenly, in both 7.62 and 5.56.  Regards

I swear, every time I set up my RCBS swager after I have not used in in a while I forget the little cup.  Glad I'm not he only one.

I have an RCBS swager and found it too slow for large quantities of brass. The primer pocket reamers I have are much faster and also leave a nicely radiused edge on the pocket. The hornady reamer is much better IMO than Lyman.

That's interesting, I found that the RCBS Military Crimp Remover, even mounted on the Trim Mate was really slow.  I can swage 6 or 7 cases by the time THAT reamer makes it to the stop.  Hornady Reamer, huh.  I'll have to check it out.

I absolutey swear by the RCBS swager combo kit. Not used on .308 yet but uniforms primer pockets in LC .223 perfectly. At first I was cussing it and having to wiggle case to get it off swager. Which didn't suit at all. After careful study and thinking of a shim to go under the bell it dawned on me that you needed to carry the stroke all the way to top on ram. Case just pops off perfectly. Am using Lee single stage press, but shoud work the same on RCBS.

The hornady reamer requires only a couple of twists and you're done. You could chuck it in a drill press and run it at low speed if you wanted.

I checked it out on the Hornady web site.  It appears you can order just the 2 tips for it and it'll screw into my RCBS Trim Mate.  $19 for both heads isn't bad at all.  It's probably worth trying it out.

You are most likely one of the lucky ones who got the adaquately large .210" head.  I'm thinking the age of my brass (1968) might have something to do with its finicky behavior.  I wonder if brass gets harder as it ages, and springs back too much when swaged?

I have the RCBS swager combo and found that it works real good when the stop rod/die body is adjusted so that the ram is cammed-over very slightly as the press arm bottoms out. Anything less resuts in somewhat inconsistent crimp removal, and too much results in a bent stop rod and dent inside the case head.

Both the Dillon and the RCBS require proper setup, and both work about the same when done right- speed is also the same once you get going. I have seen brass that had deformed primer pocket openings that were done by someone on a Dillon swager that was not careful. The swager spud was somewhat off-center resulting in a big depression in the side of the primer pocket opening, and I am sure the same could happen on an RCBS setup.

A real good tool is a 39.00 harbor freight drill press head, set upside down on the workbench with the chuck facing up. I cut off a 1 inch section of cleaning rod from the end that has the female threads. I chuck it in the drill press, and can thread the RCBS primer pocket chamfer cutting tool into it- the trick with that tool is to adjust the stop so that you only remove a small amount of material. I hold the bass on it and count to 3. There is no variation, very consistent and ensures proper priming in a progressive.

OBTW I also use a Lee case trimmer in the drill press, turning the cutter/pilot assembly and holding the shell holder assembly with vice-grips or on some I welded handles onto.

I am unpacking from a move and can send pictures of the setups to anyone that wants to post them. I now have a 400+ square foot reloading room above my 900 square foot garage!!!! party time soon!