Primer Pocket uniforming question

[savageshooter86]

I have a PMA adjustable cutter. Directions say pocket should not be entirely shiny, only shiny on outside of pocket in corners. But with my brass it either cuts and leaves shiny swirl at flash hole only or cuts entire pocket.

So not sure what to do? This is new Lapua Palma brass

 

[Sniper338]

My sinclair tool usually cuts the corners sqaure along with a tad but of the bottom of the pocket... every once and a while it will cut the whole primer pocket if the prass is outta spec some...

set it where it cuts the corners flush nice and good then run with it from there... if it cut anything else its just evening it all out... make sure to clean the flash holes after!

 

[amlevin]

My sinclair tool usually cuts the corners sqaure along with a tad but of the bottom of the pocket... every once and a while it will cut the whole primer pocket if the prass is outta spec some...

set it where it cuts the corners flush nice and good then run with it from there... if it cut anything else its just evening it all out... make sure to clean the flash holes after!

Same here with my Redding primer pocket uniforming tool.

I had my "experience" with an adjustable tool. The adjustment slipped once and I ruined a whole bunch of brass. Now it's only "fixed" tools for me.

 

[Joe Salt]

I don't cut my pockets till I fire them once, you'll get better results.
Joe Salt

 

[Dave T]

What Joe Salt said, wait till after first firing.

 

[savagedasher]

I never make any adjustment to the brass till it has ben fire. Larry

 

[JRS]

I continue to do it the way I was taught by the old timers in the game. Complete brass prep prior to firing.

When I asked Ed Watson why it wouldn't work as well after the first firing, he answered me with a question: "would you put a new set of tires on your truck and drive it before you balanced the wheels?"

 

[JRS]

Actually Donovan, it's a very good comparison. Unbalanced tires end up with cupped/dished areas. So yes, tires take on a completely different shape. Ed Watson not only produced match winning bullets, but was also a top notch competitor and pretty damned smart.

 

[JRS]

I think you missed the point Donovan. Ed didn't refer to it as a comparison. It was simply a reasonable question. Why fire form brass without consistent ignition? The dimensional shape takes place in the diameter of the pocket, not the depth.

 

[barefooter56]

savageshooter86,
If the tool came pre-adjusted from PMA you should be fine. Primer pocket uniforming is something that should be done from new "out of the box" until you discard it for every loading so you always have the primer at the same distance below flush. This is for accuracy and safety. If you have any questions I am sure Pat at PMA will be of great help to you. Suggest you contact him before changing anything.

 

[savagedasher]

Till brass has ben shoot with 40,000 plus Psi its shape will keep changing. Dasher is noted for that. Not only do the primer pockets change but the whole case does. My self I like two or more fire forming's before I prep the brass . Tires you balance them to stop vibrations to do it right you should drive a tire some before you balance it. Larry

 

[bigedp51]

savageshooter86

If the primer pockets corners are not square the primers will not be seated uniformly. Meaning square corners and all the same uniform depth with the seated primers .004 to .006 below flush.

How far below flush are your seated primers?

 

[R.Morehouse]

So if the pockets are not perfect from the factory it seems to make sense to uniform them before the 1st load and if the pockets are changing shape after firing it would make sense to uniform them at that time as well.......I think I get it...

 

[savageshooter86]

I will check later this evening. I did call Pat and we walked through it and he stayed on phone for probably 30+ minutes. He said if I can't get it he will adjust it for me with my cases specifically. So probably will do that

Anyone have pictures of what it should look like? I tried Google but no luck.

 

[savagedasher]

If the head on the case isn't perfectly flat as most aren't. Normally the head is lower in the primer pocket area and the out side is higher. When the pressure from shooting the case moves from the primer hole out ward. With the pocket uniformed before shooting the pocket after shooting will be wider at the bottom.
Larry

 

[R.Morehouse]

That makes sense to...

 

[TimP]

So if the pockets are not perfect from the factory it seems to make sense to uniform them before the 1st load and if the pockets are changing shape after firing it would make sense to uniform them at that time as well.......I think I get it...

I agree... Uniform your primer pockets on your new brass and then use the same tool to clean/uniform after each firing.

 

[savagedasher]

? have you look close at primer pockets that sized before and compared to the ones that have ben fired and sized. You will see the difference. I get 20 reload out of my cases without the primers being loose. DO YOU. Larry

 

[dkhunt14]

I have gotten 20 plus firings out of my brass in both Dasher and WSM and I uniform first. I use the WSM in matches for first firing. I also do them every loading. Matt