Primer Pocket Depth

[Thegreg]

Hello Greg,

Yes, I believe you are absolutely correct in believing that new Lapua brass should not have to be pocket cut.

It's a good sign that you have a small amount of resistance when loading the primer, that sounds good.

If it's new brass as you say, then it would seem to lead to the primers?

What primer tool are you using? LEE, RCBS ? But again as long as you are using enough pressure to insert the primer as far as it will go, then it would seem to be the primers? Again though, I have never had one instance in many many years of faulty CCI primers.

I wish I could be of more help, it's so annoying! I know from experience that these reloading problems can either intrigue you or drive you mad !

Good luck in solving the problem.

I'm using the primer attachment on my RCBS Rockchucker. I know people rate the hand held ones but you get far more leverage on the press, they are consistently seating to the bottom of the pocket, I've no doubt.

The thing that is driving me mad here is the SAAMI tolerances ALLOW this to happen! It's madness. Nothing I have is out of spec according to those tolerances, but if the primers are designed to sit below flush but the tolerance stack up allows them to sit proud then it's completely wrong IMO.

If you are unsure of your primer pocket - one of these gauges can come in handy. I suppose you can use a calliper and measure but if you have acquired brass of an unknown provenance, this can check the pockets in fairly short order.


https://www.sinclairintl.com/reloadi...prod71030.aspx

Thanks, I've fashioned a little depth gauge using a dial indicator. Calibrated it off a slip block so it's bang on.

Maybe a silly question but are you seating them firmly enough?

Yep, as mentioned above they are definitely seating down on a good positive stop.

The problem is the size of the damn things. When the physical measurements don't allow it then it's impossible to get them where they need to be.

Cheers
Greg

[aris]

Perhaps someone could stick some of their small rifle primers into a calliper and provide some measurements for comparison.

[CROWMAN]

Hello,

I have measured two primers from two different box's of CCI No. 400. Small Rifle primers.

The first one measured 0.174" diameter and a depth of 0.120"

The second one measured 0.173" diameter and a depth of 0.119"

Hope this helps?

[CROWMAN]

Hello,

Did you say that you measured new Lapua cases and the pocket depth is 0.120" max ?

Judging by my measurements, the CCi primers at my measurement of 0.120 will only just fit perfect! That is as long as you get a "full insert" into the primer pocket.

Of course if you get a batch of primers that are in excess of 0.120" , then you will have your problem of not seating flush.

Again I have never had this problem but!

Perhaps even on new brass, it might be a good idea to try a different pocket cleaner on a few cases to entirely clean the surfaces and try some primers in the cases again.

[Thegreg]

Hello,

I have measured two primers from two different box's of CCI No. 400. Small Rifle primers.

The first one measured 0.174" diameter and a depth of 0.120"

The second one measured 0.173" diameter and a depth of 0.119"

Hope this helps?

Hello,

Did you say that you measured new Lapua cases and the pocket depth is 0.120" max ?

Judging by my measurements, the CCi primers at my measurement of 0.120 will only just fit perfect! That is as long as you get a "full insert" into the primer pocket.

Of course if you get a batch of primers that are in excess of 0.120" , then you will have your problem of not seating flush.

Again I have never had this problem but!

Perhaps even on new brass, it might be a good idea to try a different pocket cleaner on a few cases to entirely clean the surfaces and try some primers in the cases again.

Thanks for doing those measurements. The CCI primers I have are mostly around the .122" mark. Some as low as .119" and a few up as high as .124". That's pretty shocking consistency.

Yes, the new Lapua brass has very consistent primer pockets, all between .119"-.120". Not much good though if most of my primers are .122"!

I ordered a K&M uniformer tool yesterday on zx10mike's recommendation. I've seen a lot of good reviews on them too so they must be pretty good. I'll see how I get on with that. I still think the primers are oversize though!

Cheers
Greg

[Black Beard]

Primer loading tools rely on the top of the rim pushing against the shell holder. Try measuring the rims or a different shell holder.

[Parabuteo]

Primers should not seat flush but slightly recessed.

Blimey, what an odd one!!

The only primer issue I had was with Wolf/Murom primers piercing round the edges. Turns out they make 2 specs of SR primer, one for .223 and one for 5.56x45, but they dont tell you that!!

[dicehorn]

I'm using the primer attachment on my RCBS Rockchucker. I know people rate the hand held ones but you get far more leverage on the press, they are consistently seating to the bottom of the pocket, I've no doubt.

I personally think the above is your problem. I have a Rockchucker but shelved the idea long ago of using the press to prime cases - you don't need that extra leverage to seat primers - seating primers is all about 'feel' especially after a few firings when primer pockets become loose and decisions have to be made to bin the brass. If a primer is seated correctly you should be able to see with the naked eye that the primer is below the level of the head stamp - my prognosis is that your press is not seating the primer deep enough.

For your benefit, I took a CCI small rifle primer (CCI 400) and measured its depth with my Mitutoya gauge and it was .121" I then took my RCBS priming tool and seated that primer into a brand new 223 Lapua case, then with a universal deprimer carefully removed the primer and remeasured its depth - now .1165". Seating the primer correctly has the effect of expanding the primer outwards to ensure a good seal in the primer pocket. Perhaps you should try that with your press method.

Maybe you have some one in your area that reloads and uses a handheld primer tool that you can use.

[Randy Bohannon]

I personally think the above is your problem. I have a Rockchucker but shelved the idea long ago of using the press to prime cases - you don't need that extra leverage to seat primers - seating primers is all about 'feel' especially after a few firings when primer pockets become loose and decisions have to be made to bin the brass. If a primer is seated correctly you should be able to see with the naked eye that the primer is below the level of the head stamp - my prognosis is that your press is not seating the primer deep enough.

For your benefit, I took a CCI small rifle primer (CCI 400) and measured its depth with my Mitutoya gauge and it was .121" I then took my RCBS priming tool and seated that primer into a brand new 223 Lapua case, then with a universal deprimer carefully removed the primer and remeasured its depth - now .1165". Seating the primer correctly has the effect of expanding the primer outwards to ensure a good seal in the primer pocket. Perhaps you should try that with your press method.

Maybe you have some one in your area that reloads and uses a handheld primer tool that you can use.

+1

This is what I was getting at TheGregg, notice how these unfired primers are taller (even excluding the legs of the anvil) and narrower than fired:

[Elwellaxe]

You are not alone I have had issues with these primers exactly the same as you, I stopped using their small pistol primers back in the 1980s I had hundreds of Sako cases & they would not seat flush, I actually broke the bottom yoke on a Dillon press seating these, the answer was use different primers, end of problem. I still use that Dillon after 35 years, I only use large pistol primers these days & again I cannot seat CCI primers in some cases so I don't buy them, strangely enough I can use CCI rifle primers with no trouble but I only use them if I can't get any other brand, however I use a pacific single stage press for loading rifle ammo. My advice try other brands, if they seat O.K. end of problem.
Elwellaxe.

[loiner1965]

i use mostly cci and reload my .223 with them and never had any issues....i do use the hand press though

[Thegreg]

I personally think the above is your problem. I have a Rockchucker but shelved the idea long ago of using the press to prime cases - you don't need that extra leverage to seat primers - seating primers is all about 'feel' especially after a few firings when primer pockets become loose and decisions have to be made to bin the brass. If a primer is seated correctly you should be able to see with the naked eye that the primer is below the level of the head stamp - my prognosis is that your press is not seating the primer deep enough.

For your benefit, I took a CCI small rifle primer (CCI 400) and measured its depth with my Mitutoya gauge and it was .121" I then took my RCBS priming tool and seated that primer into a brand new 223 Lapua case, then with a universal deprimer carefully removed the primer and remeasured its depth - now .1165". Seating the primer correctly has the effect of expanding the primer outwards to ensure a good seal in the primer pocket. Perhaps you should try that with your press method.

Maybe you have some one in your area that reloads and uses a handheld primer tool that you can use.

Thanks for the reply and for going to the trouble of trying a primer in one of your cases. I appreciate your point about priming on the press but I genuinely don't have an issue with feel on it. My point about extra leverage on the press was just to emphasize that the primers were going to the bottom of the pocket.

I tried your test with a CCI primer and it came out the exact same size it went in.....However, see part 2 of the reply below..

You are not alone I have had issues with these primers exactly the same as you, I stopped using their small pistol primers back in the 1980s I had hundreds of Sako cases & they would not seat flush, I actually broke the bottom yoke on a Dillon press seating these, the answer was use different primers, end of problem. I still use that Dillon after 35 years, I only use large pistol primers these days & again I cannot seat CCI primers in some cases so I don't buy them, strangely enough I can use CCI rifle primers with no trouble but I only use them if I can't get any other brand, however I use a pacific single stage press for loading rifle ammo. My advice try other brands, if they seat O.K. end of problem.
Elwellaxe.

Problem solved! I bought some Federal small rifle primers and they seated faultlessly. I primed 100 Norma cases and every one seated a perfect .004" below flush of the case head.

The problem in this case was the CCI primers. I don't know whether I bought some from a bad batch or what but they just would not seat properly

Following on from dicehorn's test above the Federal primers DID compress as he suggested. I de-primed one which went in at .120" and came out at .117".

Perhaps when the pockets wear a bit after a few firings I'll try the CCI again.

Cheers
Greg

[Randy Bohannon]

Very interesting, thanks for posting the follow up.