Lapua Primer Pockets

[Flouncer]

Primers don't seat, protrude out, can't even chamber. This happened to my first 100 lot of Lapua I tried to use more than decade ago in my Gustafs 6.5x55 rifle reloads. After one firing the pockets are hanked. I set the box on the shelf and went back to my Remington and Winchester brass. Primers were Federal Gold Medal match. Forward 16 years and my second reload of Lapua in 6mmBR with Federal small rifle won't seat. Tried an old set of CCI and also fail. Out of 75 cases, 50 will seat and 25 will not. Finally broke the handle on my legacy Lee Auto Prime. ^%$& I don't think I have the means to accurately measure the pocket diameter, with a standard mic and caliper.

The cases in both instances 16 years apart all loaded fine first time, then went out of gauge after firing once or twice.

What is happening ?

Can I swage the pockets safely ?

I am not wallowing in $$$ and these are neat cheap any more. The only alternative I see, if necessary is Norma cases that come up online occasionally. I have reloaded since 1997 lots of rounds, pounds of powder and 3 x 1000 primers and have never had this problem before except with some range pick up Sellier Beloit in 8x57mm which I simply tossed as I have Federal and Remington in that caliber.

Thanks for any suggestions - Mark

 

[Erik Cortina]

So you are saying they were fine the first time you loaded them but you had issues after they were fire formed? If so, did you clean the carbon from primer pockets before seating primers?

 

[Flouncer]

Yes Erik, except that I wouldn't exactly say I fireformed in the classic sense. New PacNor 4-groove barrel. After two 20-rd boxes of factory Lapua 105g scenar, I started with a new box of 100 cases. So 140 cases in all. The current load was a development with Vita N140 as Varget went away and I haven't been able to aquire any in over two years. The website shows a starting load of 25.8g and I started the N140 at 26g and went to 28.0 in 0.3g increments with no signs of pressure. Thought of one thing. I switched to a separate press with a deprimer die to knock out the primers so I can run clean deprimed cases through the ultrasonic cleaner before I neck size with a Lee collet die. Yeah, the pockets are clean, I will scratch around with a sharp pin to see if there is anything, anything left in the pockets. But as I said I have never had this happen with Rem, Fed or Winchester cases. Let me try and take some measurements before I waste any more of anyone's time. Too busy here at the house this Sunday AM and it's a beautiful day outside. Any suggestions on a efficient procedure to analyze the fired and re-sized cases would be appreciated.

 

[amamnn]

..............and your primer pocket uniformer fit the pocket fine when you originally prepped this brass?

 

[Tim Singleton]

I switched to a separate press with a deprimer die to knock out the primers so I can run clean deprimed cases through the ultrasonic cleaner

Is it possible you have the de prime die set to deep? You can be pushing the pocket down with the press. This would cause the primer to seat above flush. If the de primer pin is set to deep

I'm not sure if that is the only problem primer above flush. Or primer won't even begin to enter the pocket ?

This is a good tool to cut all pockets to a uniform depth. A lot of guys do this for consistent depth Of the primer
It may help you get your brass back into tolerance if you have pushed it with the de prime die
http://www.sinclairintl.com/reload/primer-pocket-uniformer.aspx
You can use a virgin piece of brass to set the adjustable depth collar on the cutter. Then check the problem brass. You will know pretty fast

 

[LHSmith]

^^^^^ Tim hit the nail square on the head.

 

[Tim Singleton]

^^^^^ Tim hit the nail square on the head.

Don't ask me how I know. LoL
Like everything else I know the hard way

I think the Lapua brass is thicker in the web than the Win or Rem. This maybe why the de prime die is hitting the inside of the case and you don't have a problem with the other brass.

 

[ridgeway]

Measure with a depth micrometer and that will tell the tale...

 

[Flouncer]

Thank you all. I don't have a depth micrometer but I can check and see if the decapping die is making contact with the case bottom pretty easily. So, an operator problem, not a brass problem.

My original loads were done with a Redding set in 6mmBR. No problem. The damage was after I switched to a Lee custom collet set, and a decapping die on a separate press. The damage was done by an improperly set up Lee DeCapping die.

 

[Dusty Stevens]

Lee dies are good at causing all kinds of issues.

 

[comagutsa]

ahhh the good old Lee decapping die mmmm
as i stuffed 100 cases using the Lee universal de-capping die giving the same problem as you on my 6BR
the Lee has a bigger diameter pin than the 6BR flash hole ..pushed the holes/base out wards (makes the flash hole bigger too)..couldn't believe i didn't pick up on it sooner

 

[Flouncer]

The de-capping pin measures 0.060". So it has to be the seating die depth.

 

[amlevin]

I don't think I have the means to accurately measure the pocket diameter, with a standard mic and caliper.

Your caliper won't accurately measure the primer pocket although you could get close.

Here's a $12 solution:

http://ballistictools.com/store/swage-gage-small-primer-pocket

One end is a "go gauge" and if it fits the primer pocket the pocket is large enough to receive a primer. There are depth rings cut on it as well. Just insert into a case that accepts a primer flush and see which part of the ring you want to use (Edges or center). The other end, the No-go, helps you weed out cases with primer pockets that have grown too large so you can discard before wasting a primer.

 

[jlow]

A couple of things to consider.

One is primer pockets should always be uniformed in terms of depth, yes, even Lapua. If you ever look inside the primer pocket of a new piece of Lapua brass, you will see that the bottom of the pocket is not perfectly flat and the bottom corners are not 100% sharp. Fix it with a Sinclair primer pocke uniformer – don’t buy the handle, just chuck it in a drill and work away.

The other thing is if you are cleaning them with US cleaner, it could be your pockets are “too clean” and when that happens, you will have a hard time putting primers in. It’s the same problem with necks being too clean when seating bullets.

 

[carlsbad]

Flouncer,
I had the same problem with a batch of 6mmBR Lapua brass. I had primers that were very proud--up to .015". I had to get a uniformer and take a lot of brass out of the bottom of the primer pocket on some cases. Others were fine.

just a little work but not a horrible ordeal.

Be careful with the uniformer to deepen the pocket but don't damage the circumference of the pocket or you'll have loose primers soon.

Good news is the next 2 batches of Lapua 6BR brass I bought had no such issues.

--jerry

 

[bigedp51]

I'm not saying this to start and argument "BUT" I bought the same gauge that amlevin is suggesting and it was worthless for my needs. I was checking primer pockets on mixed once fired .223/5.56 brass and this gauge is basically SAAMI max and min primer pocket diameter. And this gauge is like the story of Goldie Locks and the three bears, one end is too cold and the other end is too hot and you can't find the primer pockets that are "just right"

After using this gauge amlevin is suggesting above I ordered pin gauges in .0005 increments instead of a GO NO-GO gauge that doesn't give the porridge temperature in between.

The pin gauge below is "smaller" than the GO NO-GO gauge pictured above and it has entered the primer pocket, and this case is in my scrap brass bucket. Primer pockets come in different diameters along with the primers you buy and one size doesn't fit all.

 

[Flouncer]

biged, can you please post a link to that saami pic ? thanks!

I also realized I am lazy

 

[bigedp51]

biged, can you please post a link to that saami pic ? thanks!

I also realized I am lazy

Sorry I copied the picture and not the link, you can try Googling primer pocket diameters and look under images.

 

[RegionRat]

Must agree with BigEdP51, watch the auction sites for sets of Deltronic or gage pins.

Some large universal sets have step sizes that might be too large for every task, yet you will have at least some coverage for a wide rage of problems.

Another way is to watch the auction sites for fine increment pins in the nominal range of your task, for example sizing of primer pockets or sized neck diameters. To further the example, sets that step in 0.001" increments would be able to tell you a hole diameter to 0.001", but a Deltronic pin set for .222 would give you 12 steps above and below in steps of 0.0001".

The ability to gage your neck sizing or primer pockets with these pins makes them worth the trouble to find them.

 

[bigedp51]

RegionRat

My primer pocket standards are for over gassed AR15 rifles and the ammunition I load for my sons and my AR15s, and my son is not going to blame dear old dad for a eroded bolt face on his AR. The pin gauge I use for rejection is .0005 smaller than the GO NO-GO gauge pictured in amlevin posting and bolt action rifles are not over gassed. Meaning the AR bolt can move to the rear while there is still pressure in the barrel and the primer end up in the trigger group and possibly have high pressure erosion on the bolt face.

The person who posted the photo below said he didn't bother checking his primer pockets and when the bolt face got bad enough he would just replace the bolt.

Therefore I set my standards far above "Idiot proof" and in the primer pocket OCD range.