Primer Pocket Depth - Novice Question

[Phil3]

New to reloading, and was checking new Winchester 223 brass. When I insert my Sinclair primer pocket uniformer, the shoulder of the tool stands proud of the bottom of the case by quite a bit. I used some sheets of paper stacked together to fit into the gap and measured the paper. About .013". Is it normal to cut away that much material to get the pocket uniform? I guess it is, since it is hard to use a primer pocket tool incorrectly, but it does seem like a lot to me. Maybe the pocket edges are just rounded and all I am doing is squaring them up. ???

- Phil

 

[Hummer]

Re: Primer Pocket Depth - Novice Question

My uniformer is a Sinclair (there may be others) and I find it cuts on one side of the bottom of the primer pocket before the other.
Measure the unseated height of the primer and add .003" to that and it should give you an indication of how much you need. You want surface of primer about .003 to .004 below case head and at same time you don't want to seat primers HARD as it cracks the ignition pellet which will give erratic ignition.
You should have firing pin protrusion of about .040".

 

[BigDKC]

Re: Primer Pocket Depth - Novice Question

This is a qoute of my own from the Brass Prep thread in the stickies up above. Sure seems like alot of material to me, but so far so good on these 50 cases!


<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: BigDKC</div><div class="ubbcode-body">So I worked 50 new Winchester .308 brass through these steps last night. Took an interesting picture! It's the result of all the brass removal from the primer pocket uniforming and flash hole deburing. I was kind of suprised at how much was removed!

10.4 grains of brass removed from the primer pockets on the left, and 20 grains even removed on the right from deburring the flash holes! Just over 30 grains out of 50 cases!

</div></div>

 

[Phil3]

Re: Primer Pocket Depth - Novice Question

<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">My uniformer is a Sinclair (there may be others) and I find it cuts on one side of the bottom of the primer pocket before the other.</div></div>

Same here, but figured it was because I can not hold the cutter and case perfectly in line with one another.

<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">Measure the unseated height of the primer and add .003" to that and it should give you an indication of how much you need. You want surface of primer about .003 to .004 below case head and at same time you don't want to seat primers HARD as it cracks the ignition pellet which will give erratic ignition.</div></div>

I should be able to measure this. Right now, I will be using the Forster Co-Ax press as the priming tool, which always seats the primer .005" below the case head. The disadvantage is that it does not permit seating to a depth by feel, but it is very consistent (by design) on how far the primer sits below the case head.

- Phil

 

[former naval person]

Re: Primer Pocket Depth - Novice Question

Remember that the act of seating compresses the pellet a bit between the bottom of the pocket and the anvil. Measure a fired primer...the anvil won't be protruding after firing, and add your .003 or so to that. You can cut those pockets so deep that your firing pin protrusion won't give you the consistent ignition you desire. JMHO

 

[Phil3]

Re: Primer Pocket Depth - Novice Question

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: former naval person</div><div class="ubbcode-body">You can cut those pockets so deep that your firing pin protrusion won't give you the consistent ignition you desire. JMHO </div></div>

How can that be possible? Should not the shoulder of the uniforming tool stop excess cutting?

- Phil