What are the major differences between Rifle and Pistol primers?

[Dezynco]

I've been reloading for years, but never really known the main differences are between rifle and pistol primers, other than the label on the box.  I've been told that the spark is hotter in a rifle primer.  However, I use Large Pistol primers in my loads for my 30-30 Contender pistol because they seem easier to crack.  I also discovered that my group sizes were reduced by as much as half!  However I have discovered that by just changing the brand of primers can solve this problem also - like switching from CCI to Winchester primers.

The reason I'm asking is that I've had a hard time finding any large pistol primers, and figured "what the heck" why not use some of the thousands of large rifle primers that I have on hand for my 45ACP, 44 Mag, and 10mm.

Any thoughts?

[Lloyd Smale]

you dont want to use rifle primers in a revolver. the cups are a bit taller and will protrude a bit and in a heavy recoiling load they possibly could slam into the recoil sheild and ignite. As to using pistol primers in a rifle, ive done it with low pressure cast loads but for the most part pistol primers cups are made out of a softer material so they will ignite easier with the lighter firing pin strike of a pistol and a rifles fireing pin can possible pierce them especially if your loading higher pressures. Problem with all this advice is there so much variation between even brands of primers. Cci uses harder cup material then anyone else for all of there primers and i was told in the case of small rifle primers that the small pistol mags are basically the same primers in a differnt pack. You ran into one thing that i discovered years ago in handguns. Whenever i did an action job on a smith revolver it seemed like it just didnt shoot as well. It is the fact that you reduced the force the firing pin hits the primer and it really makes a differnce. You can experience it even in a ruger single action. Tcs too are notorious for borderline light primer strikes. Im sure that when you swithched to a pistol primer the thinner cup material allowed for a more consistant primer strike and thats one of the reasons your accuracy increased. Other then competition guns that i need a really light da trigger pull i tend to stay away from lightening the hammer spring in handguns anymore. I will lighten the trigger spring and hone the hammer and action but leave the hammer spring alone. For any gun ive found the need to lighten to an extream i stick exclusively with federal primers as there the easiest to light off.

[wncchester]

The cup thickness/hardness in pistol primers are less so they can work with the lighter pin strike.  They are NOT designed to take the very high pressures of most rifles.

[buck460XVR]

you dont want to use rifle primers in a revolver.

........unless you reload for .460/.500 S&Ws or a few other big bore revolvers that require a Large Rifle primer. Other than that, everything LS wrote is spot on.

[stimpylu32]

Dez

Check these links , should help explain it some .

http://www.jamescalhoon.com/primers_and_pressure.php

http://www.6mmbr.com/PrimerPix.html

stimpy

PS -- both are in the Useful Links Sticky at the top of the forum . 

[Dezynco]

"Ahhh" he said as the metaphorical light bulb switched on above his head!

Thanks guys, now I see!  It will not be a problem to use large rifle in my pistol cartridges - if they will ligh, and if they will seat deep enough - but it might NOT be a good idea to use pistol primers in my 30-06 with some hot loads.  With the 30-30, it probably doesn't make much difference because the pressure it not so high.

Same for any "low pressure" rifle cartridges like the 45-70, 375 Winchester, etc.

[Dezynco]

WOW! on the photos!  I wonder if the larger spark will lead to better powder burn...

When I used to shoot Black Powder Cartridges, sometimes the hotter spark could be detrimental.  The force of the spark would start the bullet and powder collumn up the barrel before the powder ignited.  This would cause poor acccuracy.  Some of the best primers for BPCR were Federal pistol primers.

Go figger!