Primers work better with cast

[DrCaveman]

The thread title describes my experience today. While shooting 7.62x39 hand loads, I experienced 4 of 5 failures to fire, using 18.5 gr imr4227 behind a jacketed 150 gr flat point. Primer was a CCI 500.

Then I proceeded to my cast loads, using the same primer. Mold used was ctl312-160-2r, and boolits weighed out to a pretty good average of 160 gr. Lube was LLA, single coat. No leading. But at least the dang primers went bang!

Nothing was different as far as the priming went. I shot 2 rounds of factory ammo to 'warm up' the 30-30, so I don't think that sort of thing would be an issue.

Any ideas? I now have to pull all the un-shot 7.62x39 rounds, and I am thinking of giving up on CCI for primers, across the board.

[boltons75]

Did you attempt a second shot, perhaps the primers just werent seated completely.

[geargnasher]

Total FTF, or failure to light the powder off?

Gear

[HangFireW8]

It might be a headspace issue. If the cast boolit is a few thou larger, or have boolit jam (engage the rifling), it can hold the primer back just enough to let the firing pin do a better job.

I was recently debugging a headspace related failure-to-fire issue in one of my old Mausers. When it finally got down to it, cartridges with case headspace below a certain thousandths of an inch didn't fire, those over did fire. The threshold was really about .001". The real culprit was insufficient firing pin extension, but it was fascinating how reliable my old cartridge headspace comparator and dial caliper was in predicting or diagnosing failure or ability to fire.

So, how are you sizing your cartridges? Do you have the tools to measure cartridge headspace at the shoulder?

HF

[HangFireW8]

...I shot 2 rounds of factory ammo to 'warm up' the 30-30, so I don't think that sort of thing would be an issue.

Any ideas? I now have to pull all the un-shot 7.62x39 rounds, and I am thinking of giving up on CCI for primers, across the board.

I'm confused, it is a 7.62x39 or a 30/30?

HF

[Wolfer]

I would suspect a seating or headspace or firing pin before I suspected the primers. It does happen but it's pretty rare

[DrCaveman]

Hang fire, duly noted. It was 7.62x39 all the way. I confused myself because I performed a similar test with my 30-30 today. With the marlin I had no problems, so maybe I shouldn't be so quick to write off CCI primers entirely.

[DrCaveman]

I probably should have also mentioned that I was using brand-new Winchester brass. I full-length sized it, trimmed it, and crimped it, but maybe the shoulder still wasn't sealing properly.

I can say that the jacketed plinkers measured about .308-309 while my cast boolits came in around .310-311. I used the same level of FCD crimp on each. I was a little concerned that the jack bullets I bought were in fact too small for my gun, but I didn't expect them to completely fail.

[DrCaveman]

Gear, total FTF. just a wimpy firing pin indent on the primer. I decided I will put them aside for my ak, bet that will set them off.

But for my sweet-shooting cz527 this is not acceptable. I am probably going to try the Federal route.

[TNFrank]

Why are you using Large Pistol Primers in a case designed for Large Rifle Primers? Large Rifle Primers are a tad bit longer then Large Pistol Primers SO the pistol primers are probably being seated in too far for the firing pin to reach them to reliably set them off. Go with a CCI #200 Large Rifle Primer and get back to us on this. ;)

[DrCaveman]

Boltons75, I tried second shots, no luck.

The more I think about it, I may have neglected to trim the cases for the mis-fire run. Being that the cases were brand new, and that my subsequent trimming of cases had no effect (meaning they were all short), I may have figured that this oversight was no big deal.

In everyone's experience, could this be the cause of primer problems?

[DrCaveman]

Why are you using Large Pistol Primers in a case designed for Large Rifle Primers? Large Rifle Primers are a tad bit longer then Large Pistol Primers SO the pistol primers are probably being seated in too far for the firing pin to reach them to reliably set them off. Go with a CCI #200 Large Rifle Primer and get back to us on this. ;)

Uhh, yeah sorry about that. Good catch. I guess I should have double checked my box before scribbling into my notebook.

I was using CCI large rifle primers, 200.

This may help with abilities to answer my question.

Thanks!

[Jim Flinchbaugh]

I've been having FTF on my new Handi 7mm-08. Also new brass.
I was wondering too if the shoulder was set to far back on the initial firing and that's why they weren't lighting off. Most lit on the 2nd hit but 2 didn't. I did find boogers in the firing pin hole and I put a lighter spring in, that reduced the FTF from about 8 in 20 to 2 or 4
I've never had CCI misfires, till this rifle

[waksupi]

I had this problem years ago, and contacted CCI. They told me their die process leaves a very precise sharp corner on the primer, and they must be seated firmly to function properly. Otherwise, the primer had to be driven forward to where usually the next firing pin fall would ignite it.
Before that, I had been priming as I would with other brands, just doing them as fast as possible. Once I took my time to FEEL each seating with the CCI, the problem went away.

[ku4hx]

The thread title describes my experience today. While shooting 7.62x39 hand loads, I experienced 4 of 5 failures to fire, using 18.5 gr imr4227 behind a jacketed 150 gr flat point. Primer was a CCI 500.

Then I proceeded to my cast loads, using the same primer. Mold used was ctl312-160-2r, and boolits weighed out to a pretty good average of 160 gr. Lube was LLA, single coat. No leading. But at least the dang primers went bang!

Nothing was different as far as the priming went. I shot 2 rounds of factory ammo to 'warm up' the 30-30, so I don't think that sort of thing would be an issue.

Any ideas? I now have to pull all the un-shot 7.62x39 rounds, and I am thinking of giving up on CCI for primers, across the board.

I don't think the primer knows, or cares, what the pellet is. I'd look for other causes.

[XTR]

I've fired thousands of CCI #200 primers in my reloads and never had a misfire.

Did you show a good firing pin strike? (seating depth , though not usually a porblem, head space, could be)


Any chance they were wet inside? (i use an ultra sonic cleaner and I've had water still in cases 2 days later if the temps were right.)

[TNFrank]

If the shoulder on the cartridge case is set back too far that'd throw off head space and put the cartridge in too far for the firing pin to get a good strike on the primer. Wouldn't matter what primer you were using since the firing pin wouldn't be making good contact with it. I'd set a factory ctg. next to some of the handloads and see how the shoulders compared or better yet if you have a set of calipers just measure it and see what the dimensions are between the two. I've used CCI primers for years before I switched to Winchester(only because they were out of CCI) and now I've recently switched back to CCI and they still seem to work pretty well. I'd look for something other then the primer being at fault here.

[prs]

Loose nut behind the stockk will cause that.

prs

[dnotarianni]

I got a couple thoughts First did you use pistol or rifle primers? Pistol primers are a touch shorter and your firing pin might not be getting a good hit due to the distance. Second if they are all light hits change to Federal primers as they seem softer to me and all my lightly sprung handguns will only fire reliably with Federals. Last of all compare the primer pocket of the new brass to an old brass and check the primer pocket to see if it is a brass problem. If the pocket is too deep you won't get good hits to set the primer off
dave