Large pistol primer instead of large rifle?

[Kawfeegod]

Well, considering that the primer market is pretty much dried up in my neck of the woods, large rifle primers are non-existant. I am sitting on quite a few LP primers and was wondering if you could sub a LP primer for a LR primer? Anyone have any ideas?

[Down South]

From what I understand, the cup on a LP primer is shorter than a LR primer. I’ve heard of it being done but I’ve never tried to use LP primers in rifle cartridges. If what I’ve heard about the LP primer cup being shorter is true then the primers will be more recessed than normal. This possibly could cause a FTF. Another thing and again from what I’ve been told is, LP primers are not as hot as LR primers. Some folks with more knowledge than me will chine in on this one I’m sure

[jsizemore]

And the primer cup is thinner on a pistol primier. It's not meant to operate at rifle pressures.

[archmaker]

Digging deep into my past I vaguely remember that the thickness of the cup material varied between LP and LR. LR has slightly thicker material to help with the pressure, where LP had a thinner material so that the weaker "blow" would fire.

That may not help.

[curator]

I use large pistol primers all the time on my cast boolit rifle loads. I do keep pressures below 40,000psi for many reasons. I get good ignition and accuracy. They do sit a bit lower than LRPs but I have never had a failure to fire in any rifle using them. Occasionally the pistol primers give better accuracy. My best .308 load with Lyman #311291 and 16 grains of Alliant 2400 shoots 3/4 inch 5-shot groups at 100 yards with LPP and 1 1/2" with LRPs--who would guess?

[cuzinbruce]

A large rifle primer pocket is deeper than a large pistol primer pocket. If the primer is seated to the bottom of the pocket, it will be unsupported at the bolt face. By the difference in depth. If it is seated flush, it may move when struck by the firing pin, causing unreliable ignition. Unsupported, it might leak or worse. Also made softer as pistol firing pins typically don't strike with as much force as a rifles. Designed for a lower pressure environment, from 16,000 to 35,000 psi for pistol cartridges, normal to magnum. Rifle pressures would probably be expected to range from 40,000 to high 50,000's. I don't think it would be a good substitution.

[jcwit]

Not recommended, thats why they make Lg. Pistol & Lg Rifle.

No further comment!!!

[JohnH]

From my own experience I have fired quite a few thousand rounds of cast boolits in rifle cases lit with with large pistol primers with no problems. We must however disucss the loads to get good working parameters. 10-12 grains of Unique in a rifle case will make anything go bang and does not need a rifle primer. I have found that 12 grains of Unique under a 120 grain boolits in a 25-06 case does give better accuracy when lit by a rifle primer, but in a tight, pistol primers work just fine. I've never been able do discern any difference between large pistol, large pistol magnum and large rifle primers when using 19 grains of 2400 with the same 120 grainer in my 25-06. Nor can I say with absolute certainty that large rifle primers perform any better than large pistol primers in the 30-30 with similar powder charges under boolits as heavy as 180 grains.

Now would I use a large pistol primer as a substitute in a standard pressure loading in a rifle case? No. Nothing catastrophic will happen. You will get pierced primers, and depending on the gas control of your rifle, you may or may not get an eyefull of gas and tiny debris. Over time, the gas will erode your firing pin and firing pin hole/bushing which will end in primers prematurely showing cratering.

Be wise. If the load you are considering is operating at pressures greater than 35,000 psi or so don't use a pistol primer. If you are using a load that is comparable in powder charge weight and bullet weight to a known good pistol load using a pistol primer, then by all means use a pistol primer.

[trickyasafox]

I never thought to use LP instead of LR with reduced unique loads, but that will certainly save me some money! LP I have a fair supply of- LR, that was getting dicey!

[JIMinPHX]

I've been told for years that rifle primers were thicker than pistol primers so that they would be able to handle the higher pressures that rifles generate. I was also told that pistol primers needed to have softer cups so that the dainty little firing pins in them could work reliably. I always just assummed that to be true. I always thought that the dimensions were exactly the same.

I just went out into the shop & measured unfired WLP & WLR primers. The rifle primer was about .004" taller. That difference is the same as the thickness of a sheet of standard 20# copy paper. The cup materials were the same thickness. The anvils looked to be a slightly different shape, but were pretty close. The pellets were different colors & the rifle primer pellet looked to be a bit bigger. I did not test cup hardness.

I've used pistol primers before with lite loads in small rifle calibers with good luck. I'm sure that there is a point where this becomes inadvisable, but I don't know where that line needs to be drawn. As always, I recommend that you err on the side of caution.

[WARD O]

Substituting LP for LR in black powder shooting is not an uncommon practice. Many seem to think the milder LP is an aid in accuracy with black powder. Black powder pressures are mild and there seems to be very little if any down side. Some say that after many thousands of round there might be minor bolt face damage due to primers setting back during firing.

It sounds like this is to be a short time substitution for you until primers become more readily available so that should not be an issue for you.

So, if you keep pressures to the levels these LP's were designed to handle they should pose no problem for you.

Ward

[Kawfeegod]

So I am getting yeahs and nays, which is what I expected. It looks as though it might be worth a shot in a pinch. I'll load a few and see what happens in my mosin.

[BerdanIII]

Add another yea; I just burned up over 1000 Magtech 2 1/2's in an M39 (7.62x54mmR) and Ishapore .308 with gallery loads with no problems whatsoever. I have also used them in commercial rifles with no trouble. The Cast Bullet Association handbook recommends large pistol primers in cast boolit loads for ex-military rifles. The only caveat I would place on this is to make sure your firing pin(s) have rounded, not sharp points.

[wildwes]

I've never tried them with cast loads, but I tried 20 rds of them in 8MM Mauser in my 1903 Turkish mauser once, and they wouldn't ignite the powder. The load was 42 grns of BL-C(2) I think, with a sierra 150 grn prohunter PSP. The primers detonated just fine, and generated enough force to push the bullet into the barrel, but not detonate the powder. I think they lodged about 4 inches from the front of the chamber. I hate to think of what would have happened if I had fired a round behind them without removing the bullet every time. And boy did the BL-C(2) make a heckuva mess in the action. Maybe they would work fine with another powder, idk

[drinks]

Before everyone gets their panties in a bunch over LR and LP primers and the supposedly .010 difference in height, try measuring the depth of the primer pocket in several different cases and several different manufacturers.
I tried about 15 and found a depth of .123 to .136 in just rifle cases.

[jdgabbard]

Ok, so we know that LP primers run the risk of not handling the pressure very well above 30,000. But what if we were to use magnum pistol primers? Since the magnum loadings are designed to operate at higher pressures it would seem these primers would be able to handle a little more...

What do you think?

[wildwes]

I don't know enough about it for my thoughts to count for much jdgabbard, but it would look to me like the magnum primers would be able to handle the pressure ok if it wasn't extremely high. Wouldn't they do a little better at igniting the powder too?

[Screwbolts]

I have a wonderful old Stevens 322C in 30/30 that likes to shoot Ohaus 180gr RNGC. this particular rifle will misfire on the first strike if I load w/ LR primers. some time ago I tried LP primers with it and have never had a miss fire with LP primers. I load a Book load of AA 2520 28 gr I believe and it has never been shot with anything but cast and LP primers for the last 5 yrs. :castmine:

Ken
CNY

[GrizzLeeBear]

I've never tried them with cast loads, but I tried 20 rds of them in 8MM Mauser in my 1903 Turkish mauser once, and they wouldn't ignite the powder. The load was 42 grns of BL-C(2) I think, with a sierra 150 grn prohunter PSP. The primers detonated just fine, and generated enough force to push the bullet into the barrel, but not detonate the powder. I think they lodged about 4 inches from the front of the chamber. I hate to think of what would have happened if I had fired a round behind them without removing the bullet every time. And boy did the BL-C(2) make a heckuva mess in the action. Maybe they would work fine with another powder, idk

Correct, wrong primer for the powder. Thats why its recommended to use a magnum primer with ball powders. The deterant on ball powder responds to a hotter, more powerful primer much better. You basically went to a weaker primer instead of a more powerful one. If you did get any to fire, did you get cratered or pierced primers?

I've only tried LP primers in a rifle load once so far. Shot some 100 gr. plated pistol bullets in a Rossi 7.62x39 single shot loaded with 5 gr. of 231. I was also worried about the primer sitting a little deeper because this rifle doesn't have a lot of firing pin protrusion, but all 10 that I loaded fired just fine and were very accurate. Would have worked with this load more, but the rifle is at the smiths getting rechambered to .303 British right now. I'm going to continue this experiment in the .303 when I get it back.

For low pressure gallery/small game type cast boolit loads I don't see any problem using pistol primers. The primer seating deeper may or may not cause problems in a particular rifle, but it seems that most of the time its not a problem.

[wildwes]

Correct, wrong primer for the powder. Thats why its recommended to use a magnum primer with ball powders. The deterant on ball powder responds to a hotter, more powerful primer much better. You basically went to a weaker primer instead of a more powerful one. If you did get any to fire, did you get cratered or pierced primers?

I figured it might have had a little something to do with the powder being a ball powder, I know they tend to be a little harder to ignite. I only tried three, because they made such a mess, if I remember right, one fired, but I may be wrong. It's been a little while, so I don't remember for sure. But as far as I remember there weren't any problems like cratered or pierced primers, just a little "clunk" sound as the primer detonated and pushed the bullet into the bore. I took the other 17 rounds, pulled the bullets, replaced the primers, and reassembled them. Problem solved. lol.

[mpmarty]

All my 308 and 45/70 cast boolit loads are with LP primers and 2400 or varget powder.
They work in my 7.62 Nato chambered Saiga as well as my Savage 11F and in 7.5X55 aka 30/284 both my Schmidt Rubin K31s. I used to use LR primers for these loads but find better accuracy with the pistol primers and save my LR primers for the 7mm Remmy and jboolit loads in the rest.

[Tom4570]

In the 90' primer scare when Iwas shooting IHMSA matches with cast boolits in my 7BR I tried small pistol primers instead of small rifle and had good results with improved accuracy. I don't see why it wouldn't work with large pistol primers instead of large rifle, just keep pressures lower and don't use ball powder as they are harder to ignite. Just my thought's. Tom

[Dumasron]

When using Holy Smokers I use Win LPP exclusively because better shots than I recommend it. For smokeless I use Win LRP when available and use a .030 wad to keep the charge back tight against the primer; seating it with a wood dowel by hand. This measure is especially important if there is a possibility of a double charge as with 5744 in a 40-70 case. It will also give more uniform velocity.

[eck0313]

Using LP primers on rimless CB loads seems to eliminate the headspace "shortening" that occurs with rifle primers in the same loads, BTW.

[RCE1]

I used LP primers extensively with my black powder cartridge shooting. I resolved the depth issue either by turning down the rims on a lathe, if the rifle was chambered with a tight rim, like my .45/90 Sharps Borchardt, or by swaging the primer pocket of the case shallower using a custom die and then recutting to pistol depth with a Sinclair primer pocket uniformer. I did this for my .40/65 and .38/50 Remington Hepburn brass. It was a lot of work. I used Federal LP Match primers when I was competing, which I haven't done much of the last few years. I don't think I'd do any of this for smokeless shooting, by the way, but we did a lot of complex stuff seeking a competitive edge in black powder silhouette and long range.

[beagle]

I've made this switch thousands of times WITH CAST LOADS and lower pressures. Works all right. I wouldn't do it with higher pressure jacketed loads.

I have encountered missfire problems in two rifles and I attribute this to the fact that the pistol primers seat deeper and were not feeling the full hit of the firing pin. One was a Winchester Legacy M94 .30/30 and the other was a Number 1 Ruger .30/06.

Other than these two problem children, it worked just fine./beagle

[fredj338]

I never thought to use LP instead of LR with reduced unique loads, but that will certainly save me some money! LP I have a fair supply of- LR, that was getting dicey!

COst of the primers is the same so not savings.
NO, one should NOT use a LP in a true rifle cartridge @ rifle pressures. Now if you are talking handgun rounds in a rifle, should be using the pistol primers anyway. The 45-70, it's lower pressure than most hanadguns, same for BP loads. Cup thickness is wrong & the dims are wrong. Use the right tool for the job.

[jdgabbard]

I'm going against Fred's logic in part. Never use then in a auto loader, however for lighter plinking loads there hasn't been any issues for me. Now a higher pressure load should always get a rifle primer. But in some ways, a pistol primer is acceptable.

[fecmech]

Back in the 70's I bought a 788 Remington in .243. At the time all I had were Federal LP primers that I used in my .44 mag. Went to the LGS and all he had was 60 gr Sierra bullets and H-380 powder so that's what I bought. At that time (1973)I went right to the top end of loads for starters so I chose 45 grs of H380, 60 gr Sierra bullet and Fed LP primer which gave me 3600 fps and turned out to be the most accurate load for that rifle. It would shoot that load sub moa all day long ( best 5 shot was .250"@100 yds)and I never found a better load for that rifle. I fired at least 500-600 rds of that load with LP primers and no problem. So can you use LP primers in rifles,I say yes you can!

[dale2242]

I have never tried LP in rifle loads.
I do however use SP primers in my 22 Hornet loads.
Speer used them in some Hornet tests and found they got better accuracy with the pistol primers.
Works for me.....dale

[captain-03]

My experience ... have never substituted LP for LR; hoever, I have substituated SP for SR during the "last" primer shortage. Were for .223 loads in ARs. Started off with several slam fires .... changed ARs --- more slam fires. Would not recommend it for auto-loaders ... These were not cast boolits - but the loads were not up to max ..... Gets your attention quick!!

[mpmarty]

In 45 years of loading 45/70 for my various rifles chambered for that round all I have ever used in them is Large Pistol primers. No worries they even worked in my re-chambered BSA Martini.

[chboats]

I have used LP primers in a 30-30, 308, 30-06, 7.65 Argentine, and 762x54R. All with cast boolit loads. All worked great except the 30-30 which was a TC Encore. The Encore was erratic. The firing pin protrusion was too short. Bought a new firing pin that had about .006 longer protrusion and put in a stronger hammer spring, the problem went away.

Carl

[bruce drake]

time to dig this article out the graveyard....
Local gunshops are starting to have no primers on their shelves. I found I was low on LR primers and went into see what they had. Only thing left was a couple bricks of LP Magnum primers set out for individual sleeve sales at about $5 per 100. So I got 5 sleeves of LPMs for cast bullet use and to stretch my LR primers for my jacketed use.

I just need to figure out what is causing our components to get short every time a demorat potentially might get voted into office....

Bruce

[reloader28]

Another yea here. It works fine for me. The only time Ive had a problem was getting to the max end of a jacketed load and I started piercing the primers.

[salpal48]

Depending On the load , I have had no problems in several Antique military rifles Beaumonts, Gras, and such