Primer Seating Depth ?

[3006guns]

I had a similar problem like the OP's, but with a box of CCI's that were so old the boxes were black and white....probably early sixties vintage and God knows how they were stored before I got them. Seemed like 1 out of every 5 didn't go off.

I learned years ago that a seated primer should be slightly below the cartridge base. If it's even with the base and can't be seated anymore, that's fine also......but in NO case should it be ABOVE the base.

But more on the problem of seating primers. I have two devices that can be used on "suspect" pockets. One is an old Lyman pocket cleaner that looks like a small reamer with a wooden handle. A few twists, tap out the junk and the job is done. On a large batch of brass however, this gets tiring in a hurry so I forked out the dough for a Dillon primer pocket swage. It's a bench mounted tool that uses a cam over center lever to shove a mandrel into the pocket, uniforming its size, and it's very effective.....especially on military brass, as it removed any crimp. But the point is that it UNIFORMS every pocket, ensuring repeatable primer seating.

[10mm Witness]

Remy - No I have not pulled the boolits. I'm sure there is powder in them all as when I shake them I can hear the powder. I have never tried just using a primer to push the boolit out of the case. I would think in some instances it might where as the primer is large enough to create enough pressure. I am afraid to pull the boolits. I only have the hammer style puller where the casing is held and abruptly stopped while the boolits kenetic energy drives it forward out of the casing. I dont want to take the chance of setting off a primer.

[Three44s]

I began cutting primer pockets deeper for my varmint gun’s.

When I found out how it saved me time fighting getting primers from protruding, I began uniforming all my brass pockets, rifle and handgun.

The heads of casings can be rather hard and I found that as a cutter dulls somewhat you get some resistance to your getting a truly uniformed pocket however. Also in doing all my brass, it gets real tedious doing so many cases.

To make sure have my pockets down to snuff, I run the cutter a short run dump the grit and build up and first of the brass shavings, then get down to the nitty gritty of uniforming the pocket. If I do not dump the initial mess I believe that the cutter is operating sub par.

The other thing I do is I use a power drill to run my cutter as my old paws can only suffer through just so much gaff. In doing a real uniform job cutting pockets I am subjecting the shoulder (stop) of the cutter and the face of the case head to unnecessary heat, friction and wear. To alleviate this I touch a very slight amount of case lube to the case to lube it.

The lube I use is the hard stuff that comes in the tub from Lyman called Unique and I use it sparingly for case sizing lube, but for case heads I am real scotch with it, not for cost but to minimize greasing things up and getting crud mixed in.

My primers are all initially seated with an RCBS hand tool that uses the regular RCBS shell holders. I like the tray that feeds it and less handling of primers is welcome.

A couple of years ago I tracked down a bench seater long discontinued by RCBS called the Standard. I was giving my hand held tool too much of a workout until I sourced this bench tool. So now I seat with the hand held and then finish seating with the Standard and rotate the case a couple of times to insure that the primers are all down fully square. My primed cases end up bottoms up in a load block and the amount of crush is visually checked.

I want my cups flattened slightly so I know my anvils are all properly set.

I also feel to make sure the random primer is still not high and thus able to be set off by closing the bolt or cylinder.

Three44s

[44magLeo]

The Dillon Primer Pocket Swage is a good tool for removing the crimps on cases. That's what it is designed to do.
It does nothing to remove primer residue or uniform pocket depth.
Primer pocket uniformers are a cutter. The cutting is done just on the end of the cutter. The sides match the primer pocket sides. It only cut the bottom of the pocket.
I use a battery hand drill to uniform pockets. I have a Lyman Shell Sizer die. I drop the case into the die, a tap on the bench so the case is gripped by the die. This makes holding the case from spinning easier.
I go slow with frequently dumping shavings out of the pocket.
I have a drill press And I might try using that next time.
As far as lubing the case head, I never thought about that much. Going easy with frequent stops keeps the case head cool. Once the pockets are uniformed they go through a cleaning cycle to be sure all the shavings are removed.
Leo

[rbuck351]

I use the sinclair primer pocket reamer. It's a solid piece of carbide and after thousands of cases it is still sharp. I use it in the chuck of a mini lathe and just push the case onto the cutter it takes up to three pushes onto the cutter to make sure all the chips are gone and it has cut as far as it will go (not adjustable). I have used it in a battery powered drill. It cuts clean and fast without noticeable heat build up so I don't use lube. They are a bit spendy but I don't think they will wear out in my life time. I don't use it on pistol brass so only have large and small rifle sizes. Small rifle also works on small pistol.

[mdi]

Several years ago I fussed with "primer seating depth" but in the end (and what I learned from priming with a Lee Loader in '69) I just seat all primers to the bottom of the primer pocket and disregard any "depth below flush" dimension. I primed my first rounds in 1969 with my 38 Special Lee Loader and started priming on my first press in '70-'71 and never had a FTF from poorly seated primers in any "stock" gun; single action revolvers, double action revolvers, single action semi-autos, DA semi-autos, DA only semi-autos or striker fired semi-autos. Never any problems with any rifle either; bolt, semi-auto, single shot. And I've never had to "reform or ream" any pockets for reliability.

Go back to Reloaderfred's post, #11 for some excellent info...

[onelight]

Several years ago I fussed with "primer seating depth" but in the end (and what I learned from priming with a Lee Loader in '69) I just seat all primers to the bottom of the primer pocket and disregard any "depth below flush" dimension. I primed my first rounds in 1969 with my 38 Special Lee Loader and started priming on my first press in '70-'71 and never had a FTF from poorly seated primers in any "stock" gun; single action revolvers, double action revolvers, single action semi-autos, DA semi-autos, DA only semi-autos or striker fired semi-autos. Never any problems with any rifle either; bolt, semi-auto, single shot. And I've never had to "reform or ream" any pockets for reliability.

Go back to Reloaderfred's post, #11 for some excellent info...

What mdi said my experience is about the same.

[Three44s]

I do not lube into the pocket but just a very slight film on the very face of the head of the case.

With a relatively small case such as 223, I use a Wilson case holder to give me more to hang onto and that reduces hand cramping with large batches.

Generally I do the pocket depth uniforming while I am making the initial length trim and am using my Wilson trimmer anyway so I have the case in that collet already.

Once a pocket is depth uniformed it is done “for life”. I spend almost no added time reseating primers that are too high. Before I started cutting pockets it seemed I was laboring with my RCBS handheld tool in order to crush primers excessively to avoid setting off a high one as I closed the bolt.

With my bench tool I am making sure my cups are flattened enough for good ignition and running my index finger across the heads and finding one a high one has become more of a formality than a reality.

Three44s