Primer pocket ?

[Jonny2guns]

So I'm preping some mixed 30-06 brass I purchased a couple years ago and I noticed a few primer pockets have been "reamed" so I measured them compared with some random brass. The random brass measured 0.208" and the reamed pockets measured 0.210". Any idea why these were reamed that large and will this be an issue with loose primer pockets?

 

[Anchorite]

Did someone clean up those pockets, maybe?

Persoanlly I don't get all twisted about the axle over primer pocket stuff. I do deburr the flash flash hole and uniform, but I’m not concerned about depth.
I hand prime, so I rely on feel a lot. I think you’ll be fine.

I‘ve never read anything in the way of a study that would change my way of thinking to primer pockets being the “most critical aspect” of the cartridge or the reloading process. I realize of course YMMV.

 

[Dave DeLaurant]

Plain old primer pocket reamers shouldn't enlarge the diameter of the pocket, since they are designed to scrape the bottom surface only. If your measurements are accurate, I would think a primer would drop free from the pocket -- the fit needs to be tight and a difference of .002" seems excessive. You won't really know until you try priming a few and seeing whether they stay put -- you could prime and fire in the rifle minus powder/bullet to see the results.

My only guess is that someone had a supply of oversize primers. I've found occasional problems seating a batch of Tulammo primers, which are very slightly oversized compared with any other brand I've used.

 

[LiveLife]

mixed 30-06 brass ... few primer pockets have been "reamed"

random brass measured 0.208" and the reamed pockets measured 0.210". Any idea why these were reamed that large and will this be an issue with loose primer pockets?

Mixed brass likely represents SAAMI allowable dimensions of minimum 0.208" to maximum 0.210" for LR primers - https://www.thehighroad.org/index.p...-and-discussions.778197/page-10#post-11403561

And don't forget to seat those primers deep as expressed by SAAMI of .008" below flush to prevent slam fires! (JK ... I normally seat primers to around .004" below flush as recommended by USAMU, especially for semi-autos):

"Here at the USAMU, we ensure our rifle primers generally run -0.003″ to -0.005″ below the case head. Maximum primer depth is -0.006″ and minimum is -0.002″."​

 

[Jonny2guns]

Not sure how this got into handgun auto loaders, I was in reloading forum when I posted it.

 

[Jonny2guns]

This is for a bolt action, but yes the primers will be seated proper.

 

[LiveLife]

Not sure how this got into handgun auto loaders

There, fixed it for you. Now, we are in H&R subcategory. Thanks moderator.

 

[Jonny2guns]

Yes, thank you.

 

[lysanderxiii]

The Army has played with variations on the flash hole, several times in the past, size, shape, off-center, burrs, etc, it really doesn't make any difference. Except Berdan primers, on average, they might be more consistent in terms of pressure and velocity. . .


EDIT:
Oh, and on a related, but tangential note, the Germans in WW2 found that Berdan primed ammunition worked just as well with only one of the two flash holes. Their machinery was set up to gang drill both flash holes in the same pass, and what happened was, due to poor materials for the drills, the drills had an increased tendency to break. This meant the line had to stop production while they replaced the drill. They did some testing and found that there was no statistical difference in performance. So, they started to replace drills only when both of them were broken.

 

[Larry in wyoming]

I recently read an article where they played all the bench rest tricks on primer pockets and flash holes etc. and it didn't make a lick of difference. Just what I read. No experience myself.

Ginex primers are widely known as being on the large end of tolerance if those primer pockets are too big.

 

[gwpercle]

I've been reloading since 1967 and can't remember ever measuring a primer pocket ...
Insert a primer ... if they go in and fit snugly ... and don't fall out ...
You are Good To Go !
Louisiana Swamp People say ... CHOOT EM !
Gary
Certified Louisiana Cajun

 

[Walkalong]

Plain old primer pocket reamers shouldn't enlarge the diameter of the pocket, since they are designed to scrape the bottom surface only.

Correct.