I've read all the threads on here regarding whether to do or not to do. Personally, I like the clean look a carbide uniformer leaves. I have also noticed on cartridges where I use Norma brass, that from the factory Norma is a bit shallower than other brass, so the uniformer works nice there as well.

Question - can you go to deep? I have a Lyman head that I use in my RCBS prep center and it has squared off shoulders.

Yes you can go too deep. You can thin the bottom of the pocket enough it can blow out,

Strictly talking pistol brass, I do mine by hand and just clean out the pocket. Been reloading since about 1989, no issues.

What I've been doing is using the uniformer until the pocket has a concentric ring evenly across the entire bottom of the pocket - no further. It's surprising how uneven some of the pockets are.

I'm getting lazy

I used to do all the prep.....all the time

Now day's it's hit or miss on full prep

I do all my brass using a hand tool I've had for years. It came w/ instructions on how to set it up. I set it up as per the directions and have never changed it. Can---you go too deep ? Sure, if your tool cuts to deep.

quote:

Question - can you go to deep?

Yes you can. Even though I think I am rationale, it turns out, I am like all the other irrational humans on this world, easily swayed by emotion and stupid thoughts. Decades after having two out of battery slamfires with Garands, which I know were caused only by sensitive primers, still, I thought that maybe reaming pockets deeper was a good safety measure. This is foolish as primers only have to be below the case head and the best reloading preventative measure is to size the case below chamber dimensions and use the least sensitive primers in Garand type mechanisms, which I do, and these primers are CCI #34’s or Tula7.62 mil spec primers.

So, after reaming these pockets extra deep, I take that ammunition to a 1000 yard match and try to shoot the stuff in my match M70. I got lots of misfires: click and no bang. I had at least 20 misfires, and the ones that went off, well I am going to blame my poor groups on poor ignition. Much easier to blame the ammunition than a lack of shooting skills and wind reading ability.


So, here is one of those cases that did not go bang when hit by the firing pin of my M70. Looks like a good hit. But it was not, the primer was too deep, and it was already a rather insensitive primer to begin with.



After the match I decided to measure the depth of the primers below the case head.


Primer seating depth on CCI #34 primers in LC79 308 cases that misfired in M70


0.004
0.004
0.004
0.005
0.005
0.005
0.006
0.006
0.006
0.008
0.008
0.008
0.009
0.009
0.009
0.009
0.01
0.011
0.012

avg depth 0.007
N = 19




Next local 100 yard reduced match, I decided to shoot that ammunition in my M1a. The basic Garand mechanism has a very powerful ignition system and plenty of firing pin protrusion. The picture of ammunition in this box, the tall cases are some of the pre struck M70 ammunition, the short cases are pre struck M70 cases that went bang in the M1a chamber. At least I did not have to pull the cases down, and that M1a had more than enough energy to make these pre dimpled primers ignite.

While I still ream pockets, I no longer ream to the crazy depths that I previously used.

And now, I have adopted for the M1 Garand, the most preventative measures possible to prevent in battery or out of battery slamfires. I sent my Garand bolt to Roland Beaver and he installed a firing pin spring that will positively prevent firing pin rebound off the primer. This, combined with my mil spec primers, will give me piece of mind in so far as my Garand.

I am going to test this combination before sending an M1a bolt off to Roland.

I use the RCBS primer pocket uniforming tool on a RCBS Case Prep machine. This tool has a shoulder that will not permit cutting too deep. It works great for me.

quote:

Originally posted by swampshooter:
I use the RCBS primer pocket uniforming tool on a RCBS Case Prep machine. This tool has a shoulder that will not permit cutting too deep. It works great for me.

I have a Lyman now, but also ordered a RCBS and a Sinclair. I'm going to measure them all.

quote:

Originally posted by swampshooter:
I use the RCBS primer pocket uniforming tool on a RCBS Case Prep machine. This tool has a shoulder that will not permit cutting too deep. It works great for me.

Exactly. The cutter is the precise size of the primer and the shoulder keeps it from cutting too deeply.

The primer pockets are generally, but not always, the right depth. If not, the tool cuts them to the right depth.

But usually, the tool just squares the right angle between the cylindrical side walls of the primer pocket and its bottom.

If I am trying for utmost accuracy, I use the tool to make the pockets uniformly deep and square. Primers set squarely to the right depth all fire with the same force.