Primers, some are flat and some ain't?

[HeathSexton]

Messing with my .243 some more today and noticed something on my brass when I primed them. I was working with 3 pieces of brass today and I noticed 2 felt them same when primed with the Lee hand primer and one was real tight. I marked that piece and every firing I had 2 pieces that looked good and 1 had a flat primer, the one that primed hard. What causes this and what fixes this?


Thanks

 

[DrMike]

If the primer pocket is punched rather than drilled (as is true for most brass), it sometimes is not true. Truing the primer pocket before the first loading will address this issue by ensuring that all pockets are cut to a minimum depth and to a minimum diameter.

 

[HeathSexton]

Thanks DrMike, so I need a primer pocket uniformer?

This was new brass, fired twice, annealed, and this is the 3rd firing after annealing. Every firing has looked just like this.

Here is a crappy pic, the flat one is on the right obviously:

 

[DrMike]

Normally, the pockets don't require truing after the first firing, so there could be another factor at play. However, the fact that you annealed them would indicate that the brass in the pockets may have flowed some. That doesn't really look like a seriously flattened primer from the picture, however. There is still a margin obvious from the picture. The pocket may have been a tad tight, and truing the pocket would have addressed this. While the primer is certainly not comparable to the other two primers, I would not be greatly concerned unless there was a pattern observed with several cartridges in this instance.

Consequently, Winchester brass is punched and not drilled. Generally speaking, it takes just a moment to true the pockets no Winchester and Remington brass. I find it worth the effort, even with my arthritic hands.

 

[HeathSexton]

I had set these out to work with straight from the bag and it was tight right from the get go.


"The brass from the pocket may have flowed some" What is going on that would cause that?


I anneal by turning the brass over a torch until it just starts to turn and then I put them in water. This is correct, yes?


What primer pocket uniformer would you recommend?


Thanks again!

 

[DrMike]

As you now describe the annealing process, it is not likely that the pocket was either deformed or softened. I would suspect that the pocket was tight from the first loading, and that seems to be indicated by your statement that it was tight from the get go. I have used several uniformers, and all worked well (Sinclair, Lyman, Haydon and RCBS). The Russ Haydon tool cut the tightest pocket, and the Lyman the loosest. I use the uniformer on my RCBS Trim Mate Case Prep Center almost exclusively now, but I still have several pocket uniformers on hand.

 

[CAhunter]

I really like the redding primer pocket tool. If you don't have a trim mate the reffing comes with an adapter for a drill. It has worked wonders on squaring the pockets. I notice its usually the bottom of the pocket more than the sides. Good luck.

 

[rick smith]

If the primer was not just below flush before firing, pressure from firing flattened it. Doesn't mean it was a high pressure load.Rick.

 

[HeathSexton]

Rick, that may be the case. I was really laying on the old Lee Hand Primer to even get that one seated.


I ordered the redding uniformer lastnight.


I have looked into my reloading cystal ball and I see and RCBS case prep station in the future.


Thanks!

 

[CAhunter]

Heath You won't be disappointed with the redding. Good luck and let us know how it works out.