CCI Primer Depth causing miss fires

[dennyo]

I have had some firing issues recently with firing reliability using CCI 450 srp. The primer is not the problem.

I think my issue is with getting consistent prime seating depth. I'm using a RCBS Automatic Bench Priming tool.

Are there Priming tools that with one pull will give exact seating depth?

 

[M-61]

I use a RCBS bench mounted priming tool after my CH wore out after 35++years.
Maybe I'm the only one but the primer is seated all the way down in the pocket that's it for me. I guess you might call it consistent but I prefer to call it properly seated.
Only problem I've had all these years was once a failure to fire but since I had not installed a primer......

 

[LHSmith]

I have used many priming tools, currently Lee for at the range, and RCBS bench mount for loading at home. I suggest to look at your rifles fire control for the problem. FWIW the primer pockets vary in depth from lot to lot (perhaps even case to case) I always use a pocket uniformer (Sinclair) on competition brass.

 

[Webster]

I have had some firing issues recently with firing reliability using CCI 450 srp. The primer is not the problem.

I think my issue is with getting consistent prime seating depth. I'm using a RCBS Automatic Bench Priming tool.

Are there Priming tools that with one pull will give exact seating depth?

The only proper primer seating depth is to the bottom of the pocket. Every case in a box of Lapua cases has a different pocket depth since they are swaged in place, not machined.

 

[dogdude]

21st century priming tool is click adjustable, shallow or deep, it puts'um where you want.

 

[jepp2]

Are there Priming tools that with one pull will give exact seating depth?

As @LHSmith mentioned, you will not believe how much the pockets vary if you don't uniform them.

This is what one looks like after uniforming. The amount removed varies greatly. The depth after uniforming varies none.

 

[Richard Coody]

Well over 40 years of reloading and I can't remember any primer failures. Never uniformed a primer.pocket. used many different priming tools over the years. I seat primers by feel. Don't need a tool that seats to a certain depth. I want them firmly seated in the primer pocket.

 

[Ned Ludd]

As has been mentioned, the RCBS bench priming tool should be seating primers all the way to the bottom of the pocket, regardless of whether there is primer pocket depth variance in your cases. One possibility to consider is that in virgin brass, the should has generally not been expanded/moved to fit the chamber. I have come across various Lots of Lapua brass where the shoulder may move as much as .006" to .009" on the first firing. Although I have experienced them directly, others have occasionally reported two undesirable effects when using virgin brass. The first is blown primers, the second is ignition failure. Presumably, both effects are related to the relatively short base-to-shoulder dimension of virgin brass, which allow the case to move forwards as the primer is struck, generating extra room for the primer to pop out, even with loads that are not hot, and/or light primer strikes. If you have been experiencing this problem with virgin brass, it may well disappear once the brass is fire-formed and the shoulder is bumped back only about ~.002" or so from the fired case dimension.

Another possibility to consider is that the CCI 450s are a magnum primer, and have a thicker cup than some other types/brands of small rifle primers. I do not know whether the CCI 450 cups may also be harder. Nonetheless, the issue could be one of firing pin protrusion and/or the age and strength of the firing pin spring. Checking the the amount of firing pin protrusion and replacing the firing pin spring might also be warranted, especially if you do not observe the same problem with a primer that has a thinner cup.

Primers and Pressure Tolerances — How Primers Vary « Daily Bulletin

by James Calhoon (First Printed in Varmint Hunter Magazine, October, 1995) In the course of talking to many shooters, it has become clear to me that the manufacturers of primers have done a less than adequate job of educating reloaders on the application of their primers.

bulletin.accurateshooter.com

 

[CharlieNC]

A couple of years ago myself and others began to experience a 25%+ rate of fails to fire on the 450s for the first time. Since seating them (same brick) more firmly this has been essentially resolved.

 

[Tucker65]

I would be looking at something going on with the bolt and firing pin instead of the primer or primer seating depth. You could have some crud inside the bolt that's messing with the proper strike of the firing pin. Have you pierced a primer recently? I've heard pieces from that can get by the pin and into the bolt causing misfires. I'd disassemble the bolt and make sure everything is clean in there. You can also check your pin protrusion and verify that's good too.

 

[gary0529]

What Tucker said.
Try the "failed" ammo in another gun-if it goes bang look to your offending rifle for some bolt inspection time

 

[J.d. Popkes]

Primal rights CPS.

 

[338 dude]

I have had some firing issues recently with firing reliability using CCI 450 srp. The primer is not the problem.

I think my issue is with getting consistent prime seating depth. I'm using a RCBS Automatic Bench Priming tool.

Are there Priming tools that with one pull will give exact seating depth?

I use the Frankford arsenal hand primer it has a depth setting very good leverage all metal and a decent price It also comes with I believe 10 or 12 shell holder’s I recommend you check one out

 

[ebb]

Sounds like firing pin protrusion is to small to me.

 

[NorCalMikie]

Could also be shoulders pushed back too far and you're getting lite strikes/FTF when the case gets pushed forward in the chamber??
Only issue I've ever had with primers was short brass and one getting wet over night. Primer went off but the powder fizzled rather than burn.
Nothing but CCI BR primers for the last 20 years with no issues.
Don't make a mountain out of it.

 

[whatsupdoc]

I have a Nucleus action that came with the lightest firing pin spring.
Suddenly one day after successfully firing around 380 CCI 450s it just stopped
igniting them.

Fired 10 rounds fine that day then it was done. Checked bolt, firing pin protrusion, spring,
headspace and case shoulder bump everything was fine.

Replaced firing pin spring with the next higher weight and it has been 100% reliable ever since.

Make sure your headspace is good and your shoulder bump is not excessive.

 

[Mickeyb]

I have had this issue in my 6x47 Laupa. Drove me nuts to narrow down the issue to overseating my primers. Some were hangfires and some did not go off at all. When I pulled the projectile in ones that would not go off, some of the powder was clumped and gold colored. Swapped over to a CPS seater thousands of rounds ago and never had another problem.

 

[dennyo]

The only proper primer seating depth is to the bottom of the pocket. Every case in a box of Lapua cases has a different pocket depth since they are swaged in place, not machined.

I am using NEW Lapua brass. Thanks for the info.

 

[Richard Coody]

I am using NEW Lapua brass. Thanks for the info.

I too use only lapua brass

New.lapua brass often has tight primer pockets. Takes some effort to properly seat them the first time. I like them that way since brass failure for me is loose primer pockets. I don't mess with the primer.pocket on lapua brass.

Has tight necks too. I usually use an expander mandrel on the necks.

 

[Ed333]

I also use the 21st Century. hand priming tool, and have never looked back. Use both CCI 450 and 400 primers, no problems. I also stick with Lapua brass.