Subing LP primers for LR primers

[Joel Chavez]

LR primers are hard to come by around here and I'm wondering if I could sub LP primers for my application. I'm reloading 30/30 with 140gr cast/lubed with C. red,2.45"oal and using 8.5gr of Unique. Thanks for your input. :drinks:

[JohnH]

Short answer, Yes

Long answer.... You'd probably be better served by using magnum large pistol primers reason being is this, large pistol primers are designed to be used with loads that typically don't generate more than 20,000 psi or so while magnum pistol primers are designed for loads up to 40,000 psi. Magnum pistol primers have a hotter, longer duration flame to better ignite heavy doses of ball powders.
That extra bit of flame may give you better ignition consistancy, at the same time a good crimp can do the same thing. They will also let you work up to maximum charges of Unique without primer related problems. (Peircing, cratering)

I regularly substitute large pistol and magnum large pistol for large rilfe primers when using loads that don't generate high pressures, and I regularly swap between the two with loads like your's at will, all depends on what I have on hand.

You may also find that your groups will become more consistant as well. Orver the last several years I've found that using rifle primers with light loads give me more flyers. The only guess I have as to why is that the higher pressue primer blows the loose powder around and fails to evenly ignite the charge. I also think that what may be happening is that the force of the large rifle primer will drive the bullet out of the case, changing the case volumn at ignition by enough to change the ignition rate. Whichever is true, (perhaps both conditions happen at the same time) I've seen decided and provable differences in groups. One would think it'd be the other way round, the weaker primer failing to give complete ignition, but it ain't so.

Use those pistol primers and enjoy :)

[WCF3030]

Yep. Works great. I use LP in my 30-30 with 9.5 Unique and 165, 173gr cast. Both PB and GC.
Also Use them with H335 and 130gr speer fp.

[Char-Gar]

The answer is yes...most likely. Rifle primers are taller than pistol primers so pistol primers in rifle primers pockets might sit a little low in the pocket. That is not necessarily a bad thing, but if you get erratic ignition that will be the reason why.

[fecmech]

I don't see any problem with what you want to do, it's certainly worth a try. Years ago I loaded both .243 and .308 winchester cartridges with lp primers at close to max load levels with good results. The pressure levels in your load certainly are not in excess of what LP primers are designed for.

[Joel Chavez]

A big "Texas Thank You" to all those that responded.:mrgreen:

[montana_charlie]

I'll pass this on (now that the experienced ones have had their say) simply because it is believed by many BPCR shooters, whose guns operate a pretty low pressure levels.

Many of them prefer LP primers in those big black powder cases for the reason stated that LR primers seem to move the bullet prematurely.
But, while they prefer to use them, and do use them, they also warn about a potential problem.

When the firing pin hits the 'shorter' LP primer, it forces it deeper in the pocket.
(That could cause ignition problems, but apparently doesn't.)

When the charge goes off, the primer is then slammed back out of the pocket, and impacts on the face of the breechblock, bolt, or whatever.

Unless the steel is up to the battering...or the face has been drilled for a hardened firing pin bushing...cratering of the breech face can occur.

So there...I said it...I can't tell you if it's true, or not.
CM

[buck1]

I would be slow to try it on anything but low pressure loads myself. My $.02....Buck

[Old Ironsights]

OTOH, I've got a few thousand Small Rifle Magnum primers - and not so many Small Pistol Magnum primers...

In either case I'm using them in Rifles (Win 92 & AR)

I'm still trying to get a useful answer as to whether/why using SRM in a .357 case (for use in a Win92) would be a bad thing...

[beagle]

I did have a bunch of missfires using LP primers in the M94 .30/30. I traced it to the seating depth. This is in a M94 with all of the new lawyer innovations and it hits a bit weak anyway.

Other than that aggravation, I've had no problems./beagle

[Arnie]

I use pistol primers in my BP loads and put .010 wad over the shell holder before i seat the primer .Not only does this buffer the flash of the primer but it also makes the pistol primer seat out further .Arnie

[LiquidLead]

There have been several threads, in the last few months, about primer substitution. I can't seem to locate all that I think I remember reading. Without stirring up a pot of dissension, would it be possible to get an amiable quorum, about the various safe substitutions, and make a sticky on the subject? :drinks:

I can understand if you guys don't think this is a good idea, but didn't think it would hurt to ask. :)

Mike

[Bass Ackward]

I am probably the biggest promoter of using pistol primers in rifle cases. But in limited situations. This position probably needs to be clarified.

When I do use pistol primers, I am using high density charges in a case (above 80%) that will not go over 45,000 psi. This is 90% of my cast rifle shooting. Another unique trait in my rifle loadings are that all are done with easily ignited stick powders. Performance under these conditions will often cut group sizes and allow a grain or two more powder for more velocity. It's just a way of starting a cast bullet off easier so it can go faster.

So again I am bass ackward, because if I want to shoot cast type rifle loads with fast powder, low density charges, then I ALWAYS use a MAGNUM rifle primer to guarantee ignition and minimize powder position sensitivity to avoid fillers.

[HORNET]

I really doubt that Joel's going to have any pressure problems with that low charge of Unique. It lights easily enough in that .30-30 case that I don't think he'll have any problem with powder position sensitivity. In a much bigger case it might be a problem and might require wierd stuff like drilled flash holes (They work for me in .270). You might also try about 12 gr. of 2400.
Old Ironsights, as long as you work the load up from a little reduced to allow for the increased input from the primer, I don't think that you'd have much trouble. You migh want to consider that small rifle and small pistol primers are dimensionally the same and that the Federal 200 is listed as small rifle/ high velocity small pistol. It might help get better ignition on some of those slow powders with lighter boolits.