Primers and Primer pockets ?

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06shooter

New member
I'll be prepping cases soon for my 3006.
I've been reading past threads on primer failures.

I bought a pocket uniformer because of some nosler cases are measuring shallower than the others.

My question is , is there a way to know if a primer is loose after seating with new or fired brass ?

If loads are below max and below max pressure , is there less concern with primer pockets stretching with just 10 firings for example ?

I punched a primer from a Remington case that Rem. says it's a kleen bore primer and this primer measures .215"
and the diameter of the primer pocket is
.206" so is .009" typical ?

Thanks !
 
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If I feel the primer goes in with little or no resistance, I will tap the primed brass on the bench top a few times. If the primer falls out, it is too loose. It is my standard.

-TL
 
A primer pushed out of a .206" pocket will typically be no more than .001" larger. You may have mic'd the oversize part of the primer that expanded out past the pocket diameter; sometimes called the "top hat."

Have you ever calibrated your measuring tool? I ask because standard large rifle primer pocket diameter is .210" to .211". Don't let the tool measure the dimpled end of the primer; just its body diameter.
 
I have some digital calipers I bought years ago from Napa , all I know to do is zero them as far as calibration.

I didn't know primers are tapered.
Are pockets tapered as well ?

When you say dimple , do you mean where the firing pin struck ?

I'll have to remeasure when I get home.

Thanks !
 
The primers are not tapered when new. It's just that the pressure of firing deforms the bottom of the cup, so that part can end up a little wider than the sides. When this is really extreme it's called mushrooming, because of the resemblance of the fired primer profile to a toadstool when the open end is down.

Primers%202015-03-06_14-21-00_zpsznlrgzri.gif


Calipers do a poor job of measuring small hole inside diameters. The outside corners of the flats touch the circle while the inside ones do not, so they tend to read too low. If you want to measure small holes you either need a set of precision pin gauges to fit in, or you need a set of small hole measurement transfer gauges to find the hole diameter by light friction and then withdraw and measure.

Caliper%20ID%20Error%202015-03-06_10-46-32_zpsntei6ybj.gif
 
OK , I inspected what you guys were saying and my calipers are good to go.
I seen the top hat and measured like you said and it's .210"
Measuring diameter for the pocket and it's like what was said , .206-.208 " .( not very accurate ) !

I inspected the calipers where the battery goes and found two screws on opposite sides of one another and I slightly tightened them down and by doing so it took the wobble out of the body and jaw blade and now I'm getting .206-.207

Thanks guys helping me out , I know there will be trial and error, so reading the incidents about reloading , hopefully will keep me safe and save my firearm from destruction .

Thanks again !!!!!
 
I also feel the primer going in and hitting bottom . Winchester goes in a little harder Federal a bit easier and Remington to easy . I have never reloaded a 30-06 brass more then three or four times . But I use a lot of surplus brass and have a bunch . I have had some primers after firing show a little soot around the cup . ( not great)
 
Thanks for explanation, that's good to know. WLR is what I'm going to start with, maybe a tighter fit will be better.
 
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