Was loading up the last of my .45 Colt brass and grabbed a loose box of Winchester standard large rifle primers instead of large pistol primers. I didn't notice the mistake until after I was done and was cleaning my bench off. The end result is that I now have 100 loaded rounds with large rifle primers in them. These loads are my "Cowboy" loads, 250gr. lead rnfp over 7.1 grains of Universal Clays.

So the question is, what is the difference between rifle and pistol primers? Enough to cause a difference in pressure? Go ahead and try and shoot them or get busy and start pulling apart 100 rounds?

Was loading up the last of my .45 Colt brass and grabbed a loose box of Winchester standard large rifle primers instead of large pistol primers. I didn't notice the mistake until after I was done and was cleaning my bench off. The end result is that I now have 100 loaded rounds with large rifle primers in them. These loads are my "Cowboy" loads, 250gr. lead rnfp over 7.1 grains of Universal Clays.

So the question is, what is the difference between rifle and pistol primers? Enough to cause a difference in pressure? Go ahead and try and shoot them or get busy and start pulling apart 100 rounds?

The main problem with large rifle primers is that it takes a harder strike to set them off. I do not believe that the pressure difference will be apparent unless you run them through your Chronograph.

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Revolver luvin' Mountaineer

REALITY CHECK!

The "MAIN PROBLEM" with using LR primers in a pistol round is SIZE - the LR primers will protrude past the base of the cartridge. In short, you have 100 rounds that are an accident waiting to happen.

It is a greater problem with autoloaders, in which a slam-fire is a very real likelihood. In a revolver, the problem may be closing the cylinder on the incorrectly-loaded cartridges.

Small rifle primers can be used in place of small magnum pistol primers, but Large rifle primers are taller than Large pistol primers. Put a caliper to one of each and you will see the difference. Amici has it right.

WG840

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Freedom above all else.

I once the same mistake in reverse- I accidentally seated Large Pistol Primers in 270 Win cases. They were recessed in the primer pocket due to the height differences in the primer cups. Thankfully I noticed this before I went any further in the loading process. So I CAREFULLY de-primed the cases.

If it were me- I would not attempt to shoot them.

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Andy

If the firing pin in your gun will set them off I wouldn't worry about them, shoot them up.
Your loads are on the light side.

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John

And if forcing the cylinder closed over the protruding primers sets one off, THEN what?

Or, when the combination of a load "on the light side" and the heavier wall of the rifle primer means the primer backs out even further, jamming the cylinder shut? THEN what?

Sir, not always. A few months ago I mistakenly primed a small batch of once-fired .45 Colt cases with WLRs instead of WLPs, and the primers did not protrude. The cases were MagTech, CBC headstamp.

I discarded the mis-primed cases as soon as I recognized the mistake (as I was putting the remaining primers away), so I don't know how they would have shot. I've read that rifle primers are too hot for pistols, and it seemed wise to err on the side of caution.

Hope this helps, and Semper Fi.

Ron H.

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Wishin' don't make it so.

As LR primers are longer than LP, that they did not protrude from a pistol case is quite odd.

I don't know whether large rifle primers are hotter than their pistol counterparts or not. I do know I use SR primers exclusively for all small primer applications. I need SR's for the .223 and the extra wall strength for my .38 Super loads. I decided it would prevent errors and simplify inventory by using SR's in all my small primer applications; notably .40 S&W.

Primers all seated flush with the case head. They will chamber in the revolver and the cylinder will spin freely. I've got a planned range session tomorrow, I'll take one of my Vaqueros and try a couple of rounds and check for signs of over pressure.

Under the circumstances you describe, I think you'll be fine.

You should be good. However, I would check the first case fired to make sure the primer was not backing out.

Got to make up your mind.

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John

And you've got to keep up with what was posted.

The OP added a post to say that the primers were FLUSH; ergo, the danger of a slam-fire is not present. It also means the lesser danger of a primer backing out is slim, especially if he shoots one and checks.

Which is what I suggested.

Make it to the range ?

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JD 500

OK, The reason I posted what I did is because I've been there and done that, I've been loading over 40 years and have made a few mistakes along the way, the mistake he made was no big deal, unless he was loading max loads.

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John

Range update, made it out this afternoon. No detectable difference between the rounds loaded with the rifle and the pistol primers. I'll chaulk this up to another episode of, "Dumb Things I've Done Reloading and Haven't Blown Myself Up, Yet...."

May all our mishaps be so uneventful.

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JD 500