Primer Pocket Depth

[klw]

I was having problems with high primers on my 357 magnum reloads. Finally bought a primer pocket uniformer. Solved the problem. Some of the brass had REALLY short primer pockets. REALLY Short.

What's the best way to measure primer pocket depths? I've got a micrometer but taking measurements with it is fructrating. Kind a sort a works but... Anyone make a little tool for doing this?

Also what's the best way to check to see if the primers have been seated to the right depth?

[felix]

No idea, Kenneth. I use the typical feel arrangement when priming. I prime all cases by the hand holding method, using the Lee dealie, even the pistol cases. Only the BR gun gets totally prepped cases. The uniformer does an excellent job, however, but not worth the time for the remaining guns in the closet. I load hard to prime cases with different primer brands, until a brand works. Pockets not deep enough then, are discarded into another bucket for yet a different primer, if and when purchased. Obviously, this method is not satisfactory for commercial loading operations. ... felix

[HeavyMetal]

Depth "mike" only wiy to check the pocket depth.
The primer pocket reamer, at least the one I have, is set up with a "dead stop" design.

Once it stops cutting the pocket is the correct depth! I use the reamer as my guage and this way all pockets are correct.

Primers should be set just a few thousandth's below the case head to prevent slam fires. I have never heard of a specific depth they need to be set at just below the case head.

Your right about the shallow pockets and you'll find a lot of brass has this issue!

[Reloader06]

Not that anyone asked but here's a link to the LASC site.
http://www.lasc.us/primerchart.htm
The Lyman large rifle uniformer that I have cuts them .010"+ to deep. :confused:So I'll be getting the Sinclair version soon.

Matt

[454PB]

I've measured primer pocket depth with a dial caliper. Use the protuding stem in the pocket, the rear of the dial caliper against the the case head.

[JIMinPHX]

I've measured primer pocket depth with a dial caliper. Use the protuding stem in the pocket, the rear of the dial caliper against the the case head.

ditto

[runfiverun]

what 454 said
and .002 to.005 below flush is the recommendation.

[monadnock#5]

My old Lyman 45th edition manual said to run your thumb over each primer as you seat them to make sure that each is below flush. The exact measurement isn't nearly so important as it is that the primers don't stick out.

I have an RCBS case prep center that makes short work of pocket uniforming, but only match brass has gotten that treatment so far, as I haven't yet run into handgun brass with pockets not deep enough.

[10-x]

Years ago I made a fixture to assure primers were seated uniformly.
Steel plate about 3" X 4" X 0.750"with a notch milled in one corner, tapped hole 1/4 X 28 TPI ? to hold a dial indicator so the stem is about centered in the plate and aligns with a small block that is drilled for the indicator stem and counterbored to fit the base of a 30.06/308 cartridge.
By chance I can get a pic loaded I will post it.
May seem a bit anal but when its right.......its right especially for serious :drinks:shooting

[Boerrancher]

On cases that I have which seem to have priming issues, tight or shallow pockets, I use my lee ram prime on them. Once I think they are seated properly, I have a small piece of flat heavy gage sheet metal on my bench that I stand the case up on and see if it wobbles. If it wobbles I know the primer is not flush, and I try and seat it a bit deeper. If the primer is seated properly the case will sit firmly on the flat surface.

I know the thought of smashing primers in place makes some people cringe, as it did me when I first started loading, but I have yet to have one go off in the press or not go off in the gun. Some of them are pretty flat by the time they are seated, but as I said still go bang. I generally as others have stated set these aside, and only use them as plinking rounds. Though I have never had one fail to fire, knowing my luck one would at the time I needed it to fire most.

Best Wishes from the Boer Ranch,

Joe

[NoDakJak]

I had a few go off while trying to seat them about nine or ten years ago. I was priming new Winchester 45LC cases with Remington Large Pistol primers and they just didn't want to fit into the hole. I never had that problem before. I pulled the rim off a couple cases trying to get them seated. When the go off in the shop the are unbelieveably loud. Damned near crapped my drawers the first time! I was contemplating reaming the pockets but finally decided to try some other brands first. I found that Winchester, Federal and CCI primers fit fine. The Remingtons were evidently oversize. I have run into tight fitting primers a couple times since then but never to the point where they would fire while trying to seat them.
Actually the various manufacturers do a remarkable job of keeping their products within manufacturing standards. I must admit however that I have seated many flat primers but none of them have ever failed to fire. Neil

[MtGun44]

I frequently find that Selier and Belliot 45ACP brass has short primer pockets
and requires LOTS of pressure to seat a lg pistol primer. I've been thinking
of sorting out the S&B cases and dumping them into my scrap brass box.

Bill

[floodgate]

MtGun44:

Don't toss those S&B cases out or sell them for scrap. Several of us have primer pocket uniforming tools and can make use of them, if otherwise in good shape. Let them accumulate awhile, and then maybe offer them as a site suport auction.

I'd be interested, for one.

Floodgate

[MtGun44]

Sounds like a plan. :-D

Bill

[GSM]

"What's the best way to measure primer pocket depths? I've got a micrometer but taking measurements with it is fructrating. Kind a sort a works but... Anyone make a little tool for doing this?"


Check them with a primer pocket uniformer - only takes a little longer than measuring and once it's done, it's done.

[Wicky]

I know the thought of smashing primers in place makes some people cringe, as it did me when I first started loading, but I have yet to have one go off in the press or not go off in the gun. Some of them are pretty flat by the time they are seated, but as I said still go bang.

Just as a side line to this - does anyone remember priming cases with a lee loader where you hammered the primers in? Only ever had a couple detonate but it sure wakes you up especially when the seating rod bounces off the ceiling.[smilie=l:

[Boerrancher]

Wicky,

I have used my fair share of the original lee loaders where you hammer in the primers. Its great isn't it, it is the only tool set ever made that allows you to smash your thumb, go deaf, and crap your pants at the same time.

Best wishes from the Boer Ranch,

Joe

[10-x]

7812

7813

7814
Here's the fixture I made about 20 years ago to check primer depth after seating the primer before loading.
Pretty easy to make plus you could make other "seating blocks" for other calibers.

[Ranch Dog]

I use the K&M Primer Pocket Correction Tool the first time I cycle a new lot of brass and primer pocket diameter and depth is a non-issue for the life of the brass.

You can buy these from K&M directly but this older gentleman doesn't have a web page to do such. A google search will make them available through different stores. The "bits" can be chucked up in a drill for turning large lots of brass.

http://www.kinneman.com/index.asp?PageAction=VIEWPROD&ProdID=124

[sundog]

I just finished prepping a batch of new PRVI 7.5x55 brass. I used a Lyman primer pocket uniformer with no issues. Also used a military crimp remover to chamfer the very square edge of a tight primer pocket. Fed primers loaded rather hard by hand in the first hundred (Lee hand held primer tool). Rem primers fit just fine on the next hundred.

As an aside, I also deburred the flash hole. After the first two or three, I was glad I decided to do that. There wasn't very much to deburr, but the flash holes were rather tight, so this procedure uniformed them.

I use my Lyman primer pocket uniformer all the time. If it cuts to deep, I sure can't tell. More often than not, if it does anything, it is just cleaning and squaring the pocket and not really removing any significant amount of material.

[Ranch Dog]

That's a good point sundog, I use the K&M flash hole tool. It is amazing how ruff they are.

[Junior1942]

+1 more vote for the Lyman primer pocket uniformer. Guys, buy brass in quantities from Starline or Sinclair even in quantities of 250 or 500. It'll be from the same lot #. Use the Lyman primer pocket uniformer, and flash hole deburrer, on the brass and live happily ever after.