Lapua 6BR primer pocket depth

[4xforfun]

I baught 200 new (plastic blue box) Lapua 6br casses this spring. The first thing I do after I get the neck bumped up and squeezed back down is uniform the primer pockets. I baught a Sinclair tool made especialy for the 6br Lapua casses (evedently they differ a little from the Rem's PP). I have been using a Sinclair tool for MANY years....love em!!. Anyway....I noticed that I was only getting material off of just a very tiny bit of the extream (bottom) edge of the pocket.....like they were a little to deep on about 95 % of the cases. Baisicly just squared off the edge. I mentioned this to one of the guys who has mountians of experince with the dasher. He said that they will "pop out". Those are my words, not his. All of the other (old stuff) 6 BR brass that I have done took brass from the whole bottom of the PP.

I have 3 firings on these brass now and nothing has changed....just shining up the very edge on about 95%...some I can't even get the carbon out. The loads havn't been super hot....32.6 RL15/ 105 vld/smk/amax.

Any need to fret over this? I am still working on load development...the 108 BT's look very promising.

Thanks,
Tod

 

[in2deep]

For what it's worth I bought the K&M tool to do the same thing on my new 6BR Lapua brass (older style in the gold box) and it didn't remove anything either so you have to wonder about it.
They shoot under an inch at 300 yards when it's calm and I have to think that it's not worth bothering with primer pockets with Lapua brass.

 

[6BRinNZ]

I haven't bothered using a tool on the lapua primer pockets until reading this thread...mostly because Lapua is so good there doesn't appear to be a lot of benefit in improving it. I run hot loads in a 6BR so maybe I should start using a tool on the pockets as the depth changes due to hot loads is allowing inconsistency to creep in?

 

[in2deep]

That is interesting about the pockets expanding/contracting and I have been puzzled by a similar experience in that for the first 6 firings or so the pockets gradually got looser as clearly noticed using a hand-held priming tool and it seemed the pockets would soon not hold the primers but then after subsequent firings they firmed back up to where they started and now after 10 firings things are good again.
So they seemed to clearly go thru a change of hardness/diameter just as the necks have gone thru the same changes as I don't anneal and they are now much more consistent than the first few firings when going thru the heat/hardness changes.
Maybe the K&M tool needs a second chance now.

 

[artbosco]

I bought 200 new (plastic blue box) Lapua 6br cases this spring. The first thing I do after I get the neck bumped up and squeezed back down is uniform the primer pockets. I bought a Sinclair tool made especially for the 6br Lapua cases (evidently they differ a little from the Rem's PP). I have been using a Sinclair tool for MANY years....love em!!. Anyway....I noticed that I was only getting material off of just a very tiny bit of the extreme (bottom) edge of the pocket.....like they were a little to deep on about 95% of the cases. Basically just squared off the edge.

I use Lapua exclusively in my 6PPC and 30BR. As good as Lapua is, it is not perfect all the time.

You will find, on occasion, that you will remove some or a lot of brass from the bottom of the pocket, or just the sides, or just in the bottom corners [squaring off the edge], or a combination of the three situations just described.

In all the years that I've used my Sinclair Primer Pocket Uniformers, on brass that's been shot multiple times and using the uniformer for pocket cleaning too, I've never had loose primers. If others say that they have, they must be loading EXTREMELY HOT, inordinately hot.

The 6PPC and 30BR have stout loads with very high pressures because that is their nature, especially when driving them with competitive loads, but in all the years I've been doing that, I've never had loose pockets ... ever.

 

[RDavies]

Doesnt Sinclairs have 2 different small rifle primer pocket cleaners, one for regular small rifle and another for PPC/BR cases? I know I bought a 2nd one a few years back and while one will get to the bottom, the other doesnt?

 

[CoverDog]

Yes they have two different ones. One for regular SR cases (.123" deep) and the other (.125" deep) for Lapua and Norma brass only. That's what the ones I have measure.