Anyone using pistol primers

[DonT]

Is anyone using large pistol primers in their CB loads. I shoot 45-70 and 40-65 and 30-40 Krag with AA5744 and Alliant 2400, all very reduced loads for target shooting only.

I am having a dickens of a time finding large rifle primers and recently stumbled into a cache of large pistol Primers (CCI standard not magnum).

Any thoughts on whether they will work or not, consistence, etc??

Thanks.. DonT:confused:

[madsenshooter]

Although they are the same diameter, they are thinner. I just used some in my Krag loads, which I haven't fired yet. But it was immediately obvious that they seated further in the case than a standard large rifle primer. A fully seated large rifle primer is only about .004 below the case head, the large pistol is a whopping .016 below it, and I don't know if there's enough firing pin protrusion to hit it. Even if does, it's certainly going to effect lock time. The cup of pistol primers is thinner too, and you'll get false pressure readings as compared to a large rifle primer, meaning a normal pressure load might flatten a pistol primer. Since you piqued my curiosity, I just stepped out the back door, a Krag will go bang with a large pistol primer, however the thinner cup is pierced as it expands rearward. This is with a mild load of 34gr of 4895 behind a 168gr cast boolit. Luckily the rest of the bunch I loaded was with large rifle primers and I just got back from buying some large rifle magnum primers (all the local gunshop had). I forgot to note, my Krag has a heavier than standard Wolff striker spring in it, it may not have pierced with the standard spring.

[BruceB]

Large Pistol primers work fine in Large Rifle pockets for cast loads.

In the recent past, a year or two, I've been using LP primers by choice in such rounds as .32 Special, .35 Remington, .30'06, .30-40 Krag and .303 British. There have been NO misfires and NO perforations of the primer cup in at least ten different rifles, and many rounds fired. Ballistic uniformity seems excellent.

Not only that, but in most of my rifles the LP primers seem to yield slightly tighter groups than do Large Rifle primers.

I now save the LR primers for full-power jacketed loads, and for higher-pressure cast loads. The sole exception to this is my use of CCI#34 "Military" primers for cast -bullet rounds in the M1A, and these are used for their mechanical functioning attributes, not the ballistic performance.

[Mtman314]

I have a book that shows that large pistol average cup base thickness is .018.
The Large pistol Magnum primer is .023 average base cup thickness which is the same as the large rifle and large rifle magnum. It also says that if you use the Pistol primers for rifle that it isn't recommended and though it will work you do so at your own risk. The pistol primer cups are made from a thinner or sometimes softer metal than rifle primers due to the more pressure from the propellant in rifles. BTW, small pistol magnum is also the same thickness as small rifle. It also says that since the firing pin spring is stronger in a rifle than in a pistol using regular pistol primers for a rifle could create pierced primers. be aware and be safe.

[madsenshooter]

The one I just fired and pierced was a large magnum pistol. I guess my charge of 4895 made enough pressure to force the primer back, but the 26lb striker spring (vs the standard 18lb) held the indented portion forward until the two separated, wonder where the little circular piece went? Smaller charges, and standard springs might work, but I don't think I'll try it again now that I have some LR primers. I can't save cups with holes in them for future use with match heads!

[RayinNH]

The primers with the holes you save and use a fuse in them :kidding:...Ray

[DonT]

Thanks for the input folks it is appreciated.
The loads I am using are pretty light and all with cast bullets. The 45-70 uses 25.5 of 5744 with the 40-65 using either that or 18gr of Alliant 2400, both in the 1200 fps range...

Again thank you..
DonT

[ph4570]

I use nothing but large mag pistol primers in my 45-70 target loads with 16 grains of unique. My comparison tests with large rifle primers are not extensive but do suggest smaller velocity standard deviations with the mag pistol vs. large rifle.

[dromia]

I use Large Pistol primers almost exclusively in all cast boolit rifle loads with powders up to and including Vihtavuori N120 (say Reloader 7) burning rate.

Why? because the work very well giving as good as and most times better SDs and more consistent groups on the target.

[missionary5155]

I have also used Pistol primers in cast loads. Pressure is pressure. 30,000 psi is the same in all occassions. 357 mag has a max of 46,000 so Presure wize it would work.
Problem can come up with igniting some of the slower powders in rifle. The flame is not as hot/burns as long. But with easy to ignite powder like Unique I have never seen ignition problems.
44 mag is listed at 43,500 so again pressure is always = under same sitiuations.
Mike in Peru

[klcarroll]

I agree with Mike: .......Pressure is Pressure!

I have used large pistol primers in all manner of reduced rifle loads. (Cast Boolit, Sub-Sonic, etc.)

As long as you stay with easy-to-ignite powders, and "pistol-range" pressures, ....you won't have a problem.

Kent

[dbldblu]

I also prefer LP primers for cast boolit loads. I feel comfortable using them up to 40K but rarely get anywhere near that pressure. I have one old rifle that tends to pierce LP primers so it gets LR.

[MtGun44]

My Mauser 95 puts a hole in pistol primers, serious firing pin mass
and spring.

Aside from that - like the man said PRESSURE!

Work on pistol pressures and you'll be fine. Try rifle pressures and
not.

Bill

[BruceB]

Quite a few posters are referring to staying with "pistol pressures", and how everything will be A-OK when using Large Pistol primers in rifle cases so long as we abide by this "rule", as if we're walking the tightrope.

Horse feathers. What are "pistol pressures"?

Virtually all the pressures listed for the max-loaded .41 Magnum in the Lyman CB handbook are treading VERY close to 40,000 cup. The .44 loads run just a tad lighter, but most are still well-over 35,000 cup. In Small Pistol cases, like the .357 and 9x19, again the pressures run right up against the 40,000 figure.

These are also PISTOL pressures, ignited with PISTOL primers, and the loads have served well at even higher levels than those quoted, for decades, and with pistol primers.

I will state again, that I've had no incidents of cup perforation in Large Pistol primers, even in the military rifles that deliver a heck of a whack to the primers. These include the '96 and '98 Mausers, Krag, Lee Enfields, Mannlicher-Schoenauer and others. I like the way the LP primers work for me with cast bullets, and have no reservations whatever about continuing to use them in this role.

Pressure, as the man said, is pressure.

Maybe I should try a comparison test with some JACKETED loads and both rifle and pistol primers, just for the pure-dee hell of it. With proper precautions in place, it might be interesting.

Note that some of those "pistol pressures" (sparked with pistol primers) are very close to RIFLE factory-load pressures in such rounds as the Krag and .30-30.

[smokemjoe]

I have used over 6,500 LPPs in my 35 Rem. Match cast bullet rifle, , like 35 grs. of V. 135, 140, 30 grs. AA2495, My 40 X action hads miss fires with rifle primers, Loading now 41 Swiss with L.P. now, Trying to save my LR primers for the 06 with cast bullets, Hope this help.

[madsenshooter]

Must be my striker spring, I'm going to try some lower pressure loads first, if it still pierces the LMP primer, then I'll change the spring, or shoot another Krag that doesn't have the Wolff spring. I got 99 more of the LMPs to use up. Pressure is pressure, including that of the striker spring. Calculate the pressure on the tip of the firing pin with a 26# spring, no doubt there's someone here who could, but it would require more precise measurements of the tip than I care to take the time to make. I would say that if you're getting up to the pressure required to move the primer back in the cup, whether of not it pierces is going to depend on striker or firing pin protrusion and the spring pressure on it. When you do your comparison Bruce, give us an idea how much pressure it takes to move that deeply seated primer back.

[klcarroll]

Quite a few posters are referring to staying with "pistol pressures", and how everything will be A-OK when using Large Pistol primers in rifle cases so long as we abide by this "rule", as if we're walking the tightrope.

Horse feathers. What are "pistol pressures"?

............Note that some of those "pistol pressures" (sparked with pistol primers) are very close to RIFLE factory-load pressures in such rounds as the Krag and .30-30.


I really don’t think the phrase “Pistol Pressure” is all that ambiguous! ……As you said yourself, this “pressure range” is typically defined as having a “ceiling” in the vicinity of 40,000 CUP.

When I responded to the OP’s original question, I used the phrase “Pistol Pressure” to clarify that my endorsement for the use of pistol primers did not extend BEYOND that general range. ……..An important point, considering that some of the newer rifle rounds, like the .300 Winchester Short Magnum, show observed max pressures in the 62,000 psi range! (…..PSI now being the unit of measurement with the newer “strain-gauge” technology.)

You are quite correct when you point out that older rounds like the 30-30 and 30-40 operate in the “Pistol Pressure” range: ……And if circumstances required it, I would happily use pistol primers in those rounds.

Kent

[madsenshooter]

It appears the striker spring was the problem in my case. I swapped bolts and fired a load with 16gr of Blue Dot. The primer came back to flush, which gives a bit of a false pressure reading, it flattens a bit more than a LR primer, but I know the load to be safe. No piercing of the LMP primer with the standard striker spring. I don't think I'll try the same load with the Wolff spring, I don't like gas running around in my action, not even at pistol pressures.

[Gerry N.]

The one I just fired and pierced was a large magnum pistol. I guess my charge of 4895 made enough pressure to force the primer back, but the 26lb striker spring (vs the standard 18lb) held the indented portion forward until the two separated, wonder where the little circular piece went? Smaller charges, and standard springs might work, but I don't think I'll try it again now that I have some LR primers. I can't save cups with holes in them for future use with match heads!a

Look for those little discs of primer cup inside the bolt.

I had some Winchester White Box Metric in 7.62X54 made in the Czech Republic that my Finn M39 punched firing pin hole sized bits out of. They went into the bolt, jamming the rifle. I ended up pulling the bullets and using the primed brass for cast loads. American made primers gave no trouble in that rifle.

Gerry N.

[madsenshooter]

Well, I let you guys talk me into this and I've loaded a bunch using both Federal Mag Pist Primers, and a few with CCI Large Pistol. Just fired one of the CCI's using 12.5grs of Blue Dot, and the regular striker spring in my Krag, and it pierced. Perhaps because the cup is .005 thinner than the magnum which worked ok. End of this experiment for me, you guys have all the fun you want to with em. It appears that the cups just aren't up to stretching as far as they have to in order to come back flush with the head without breaking at the indent. If I had to use them, I'd go through the hassle of making an aluminum gasket to bring them up to LR height below the case head. But I don't have to for now.

[JKH]

madsenshooter,

Have you inspected your firing pin tip? Regardless of striker spring weight, if the tip is damaged, chipped, etc. it will still pierce primers. At this time it may not be sufficient to pierce a standard large rifle primer cup but can the thinner pistol primer. I have run into the issue with my Garand's, one had what for all intents and purposes an apparently like new firing pin but would regularly pierceprimers on one particular brand of surplus ammo, I inspected it under high magnification and found a tiny chip situated so that it created an almost chissel shape to the point that was not apparent to the naked eye, swapped it out for a new pin (nspected first!) and the problem dissapeared.

Just a thought, the firing pin on that Krag isnt exactly a youngen!

Jeff

[madsenshooter]

I've used a couple different bolts with different weight springs, could be the Krag just has a bit too much firing pin protrusion to use with pistol primers (I'll hear it now from everyone that used them in Krags). No loss, I found my Blue Dot loads works better with LRM primers anyway. See the pic under Krag target analysis.

[StarMetal]

I use small pistol primers in my 22 Hornet cast loads and they made a major improvement in the accuracy. I felt with such a small case that the small rifle primer might be blowing the bullet and powder out of the case up the bore before the powder ignites. I also use large pistol primers in my 6.5 Grendel in my AR15 when I'm using formed 7.62x39 brass. This too for my cast load and for the same reason as the Hornet. Accuracy improved on the AR15 too from switch from the large rifle primer.

Joe

[rhubarb]

I have used small pistol in an AR due to lack of small rifle primers. Specifically, CCI550 SP Magnum with a mild charge of IMR3031 with a cast boolit. Absolutely no pressure sign.

Small pistol primers are the same diameter and depth as small rifle.

[captain-03]

Loaded 250 .223 for the AR with small pistol magnum primers. I can't seem to tell the difference in either pressure or performance ...

[Dan Cash]

The one I just fired and pierced was a large magnum pistol. I guess my charge of 4895 made enough pressure to force the primer back, but the 26lb striker spring (vs the standard 18lb) held the indented portion forward until the two separated, wonder where the little circular piece went? Smaller charges, and standard springs might work, but I don't think I'll try it again now that I have some LR primers. I can't save cups with holes in them for future use with match heads!


The missing circle from the primer might be a tiny metal "doughnut" that is now forced back over the firing pin. This was a problem with early M16 ammunition and rifles. The firing pin would collect enough doughnuts that it bound up and would fail to fire.

On using large pistol primers in lieu of large rifle: As noted, the pistol primers are shorter than the rifle primers and set back against the bolt face upon firing. This will eventually result in cratering of the bolt face around the firing pin hole. Kermit Hoch of Kermit Tools makes a swage to modify the primer pocket of black powder cartridges to accept pistol primers. His tool could presumably be adapted to modern cartridges.

A paper wad underneath the pistol primer will cause the primer to be seated at the proper depth in a rifle cartridge and sometimes improves accuracy in black powder cartridges. I have never tried it with smokeless.

Dan