Uniforming Primer Pockets

darkgael, there is a lot of variables that go into accuracy, but I feel with clean brass your sizing measurement's will be more percise, then it up to you and your rifle. Reloading we are dealing in thousandths.
 
Gunplummer:

The primer pocket uniformer tool is used for standardizing the depth of the pocket, not the diameter. Commonly used for '06 loads for the Garand to help prevent slam fires by ensuring that the primer is seated below the level of the case head. I find that Federal cases in particular need reaming with the tool to lower the seating depth slightly.
 
pockets

arkgael, there is a lot of variables that go into accuracy, but I feel with clean brass your sizing measurement's will be more percise, then it up to you and your rifle. Reloading we are dealing in thousandths
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So...the general answer implied is that we do not know if there is any measurable effect on accuracy.
Primer pocket uniforming has nothing to do with sizing measurements.
I do understand the usefulness of uniform pockets as noted about Garands and slamfires. That is a safety issue more than an accuracy issue.
 
Deburring flash hole should only be deburred once to the case. Could the same apply to the primer pocket, goes the depth change with multiple firings.
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I have flash hole reamers, I have never found a flash hole that required de-burring, but I have the reamers JIC. I also have a flash hole gage. I also have shell holders that fit.

Again, I ask "Who measures?" Before the Internet reloaders could measure the diameter of the case head, without a way to measure pressure on the chamber reloadrs had to find another way:eek: , they realized the case was in the chamber so they focused their attention on the case and the effect pressure had on the case when fired. I have fired cases once that took on the appearance of having been 100 times. Needless to say I shortened the life expediency of the case to 'once fired'.

The case would not fit a shell holder, my flash hole gage did not touch any part of the case going in until it bottomed out. Point? The case head expands .00025" for the first firing. I know, it is the primer that gets most of the attention. If the flash hole increases in diameter, the primer pocket expands. When the primer pocket expands the case head shortens from the top of the cup above the web to the case head. So the answer is yea, the primer pocket shortens when the case head is crushed. But, Who measures?

I use the Primer Pocket Uniformer with an RCBS case prep center. I am iniformer the depth of the primer pocket or I am cleaning the primer pocket.

Then there is the slide and glide method for shooting. I do not lube my cases. I control case travel with the length of the case from the shoulder to the case head. 'AND THEN' There are those that assume. I do not assume the firing pin strikes the primer and then the whole thing, the bullet, powder and case takes off for the front of the chamber 'and then' the primers is crushed. I have killer firing pins.

F. Guffey
 
Forgive, I left out the part about the shoulder of the case hitting the shoulder of the chamber 'sooo hard' the case shortens between the shoulder and case head, and then, sometimes I ask "Is there something else going on there that is not being considered?

I do not assume.

F. Guffey
 
darkgael, uniforming primer pockets has everything to do with measurements. A uniformer cuts the pocket to the proper depth. How accurate is a slam fired round.
 
I assume you are going in with a reamer to get a standard diameter.
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The primer pocket uniformer only cuts depth, I have used them on crimped primer pockets, but it makes for some tight primers.

then there is that part about folding the flash hole, the flash hole has equal pressure on both sides, meaning the flash hole will increase in diameter and the case head can crush. There are a few reloaders that uniform the diameter of the flash hole.

I have a friend that had a problem with his award winning 45 ACP. He allowed the slide to slam shut, it opened and closed again etc. He called another friend, he chambered one round, same thing. It was way past time to clean the pistol, the firing pin was stuck. And yes, he had holes in the roof.

F. Guffey
 
Sizing

CW: Agreed...slam fired cartridges are not going to be very accurate. Unless, however, you are loading for a Garand, the slamfire danger is virtually non-existent.
Your original comment referred to "sizing measurements". My response was written using the same term. Somehow the "sizing"part got left out in your post #26. There are a number of important measurements and adjustments that need to be considered when sizing a case....primer pocket depth is not one of them.
 
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Just my 2 cents here. There was some tests ( studies ) done on primer pockets. Tests showed that clean ( New look ) primer pockets when seated with primer did have more gas leak between primer and case then primer pockets that were left dirty. Reason being, the Carbon build up helps seal the primer tighter in pocket forcing all gas ( explosion ) through Flash hole. While Accuracy tests were never done, MV test were- MV in un cleaned primer pockets was much better.
Most benchrest shooters do NOT ream primer pockets other then when brand new brass is purchased just to uniform them, Flip side is, Most Benchrest shooters only shoot there brass very few times before it is replaced with new brass. I have 6BR brass that is going on 28 times reloaded now. Reamed pockets when brand new, Have not since then. primers still seat fine to right depth.
 
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I uniformed my pockets every firing , after getting a post from 4runnerman I only uniform the case once. Thanks again 4runnerman. Made perfect sense.
 
CW308- Your Welcome, but take what I say along with everyone else with a grain of salt. I just spend a lot of time reading and reading. At my age it keeps my mind going:D. I have read a million things and tried them all. I keep what seems to work and forget the rest. I think I have OCD sometimes ( ok well most of the time). I am never happy with what I shoot no matter how good it is. I keep trying to outdo the last load or make the target smaller or farther away. It never ends, but I also can say it never gets boring either. I shoot to much, and I spend to much on reloading. Heck I got my 6BR 3 years ago and I have 3 barrels shot out in the reloading room already.
 
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