small rifle primers for pistol cases

[Black Jaque Janaviac]

From what I understand, small rifle primers just have a beefier cup, but otherwise throw no more flame nor is it hotter than small pistol primers.

I tried a couple empty cases in my 9mm and the hammer strike is sufficient to ignite them so misfires shouldn't be excessive. So is it crazy to use small rifle in lieu of small pistol primers for 9mm and .357 mag?

[fcvan]

Well, it can be done but why? Yes, heavier cup, yes I have seen reports that the priming compound/burn rate is similar. But, that was for one manufacturer so not the same.

I did read of a guy who accidentally loaded small pistol primers in .223/5.56 rounds. Lighter cup resulted the floating firing pin touching off the whole magazine. Somebody on here suggested he alternate those rounds with properly loaded rounds. Effectively, 2 or 3 round bursts. Personally, I would have just shot them through a single shot or bolt gun.

Nothing says 'big trouble' like ripping off some rounds that by design make the gun go auto. I had a buddy that bought a used CAR 9mm and to the range we went. First mag dumped and freaked him out. He broke the rifle down and went straight the the local gun shop. 30 minutes later he was back and happy. But I think he had to check his shorts. He was just sure that somebody heard him 'let her rip' at the range. New firing pin and he was good to go.

[Rcmaveric]

Yes it will work. Small riffle is closer to Small Pistol Mag Primers but stronger. From experience in my 357 Mag. Work up a safe load. Dont just change them will nilly. They are different and can quickly make a safe load unsafe. The cups are also stronger.

Small Pistol, Small Pistol Mag and Small Rifle all have different loads in my 357 Mag.

Sent from my SM-G965U using Tapatalk

[stevenjay1]

i can only echo what others are saying. it can be done but why do it? I guess it times were hard and supplies limited and you needed the ammo, you need to use what you have. Otherwise, use the correct primers for the correct ammo. Steve

[leadhead]

When I shot IHMSA, I had a Freedom Arms .357 that I always used
small rifle primers. I seem to remember it being said that FA
recommended using small rifle primers with the hot loads. I think
they had stiffer hammer springs in them. It's been a long time ago.
Denny

[fast ronnie]

I messed up a couple weeks ago and put some Winchester magnum pistol primers in some .223.
About a dozen got mixed up with other stuff before I caught the problem. Mixed with too many others. A least I didn't drop the other 3 or 4 hundred in that bin, but it took me a while to take apart the ones I had separate.

[Outpost75]

Small rifle primers similar to the Federal 200 and Remington 6-1/2 have a base metal thickness of 0.018 + 0.0015/-0.000 and closely resemble the primers used in military cal. .30 M1 Carbine and 9mm M882 ammunition. If your pistol or revolver has stock factory springs and produces a copper indent of 0.011-0.012" on the "C" size .225x.400" copper crusher in the government gage holder, it will set off those primers. Revolvers having after-market spring kits to reduce trigger pull, bobbed hammers or DAO conversions which reduce the hammer arc and result in a lighter indent will produce occasional misfires if the copper indent is not at least 0.010" as measured with the "C" size copper and government gage holder.

"Heavy cup" primers of the type used in 5.56mm rifle ammunition such as the Federal 205 or Remington 7-1/2 have a base metal thickness of 0.024 + 0.0015/-0.0000" and require a minimum copper indent of 0.018" (minimum for the M4 carbine) on the copper using the government gage holder. Attempting to use those small rifle primers in pistol and revolver ammunition you can expect frequent misfires.

The fly in the ointment is that while the drawings for the gage holders are in the public domain, and Pacific Gage and Tool or JGS can make them for you, the coppers are not available to the gunsmith trade, but only to the gun manufacturers, government labs and their contractors. The last time I bought any (2001) the minimum order was 1000 coppers and with the necessary government certs they cost about $1 each.

So the work-around is to assemble 100 rounds in either new or once-fired brass, seating primers fully by hand, in a clean primer pocket. If the gun runs the entire hundred with no bobbles pronounce it good. If you get one misfire out of 100, then repeat the sample again, and out of 200 rounds accept on 1 misfire, reject on 2. If pistol fails this test, check driven protrusion to be in the range of 0.028-0.032", correct if necessary and retest. If that doesn't work, change primers or ammo, or try shimming the hammer strut to give a bit more whack.

[megasupermagnum]

It has been my experience that small rifle primers are closer to small pistol magnum primers. It is not crazy at all to use a SR in a small pistol primer cartridge. Small primers, both pistol and rifle are not nearly as standardized as large sizes. Give them a try, you have nothing to loose, just be safe as always.

[Black Jaque Janaviac]

Well, it can be done but why?

My local gun shop is sold out of small pistol primers - that's why.

A secondary reason is that my 9mm has an inertial firing pin - so it immediately retracts after striking the primer. This leaves the firing pin channel wide open and the primer is unsupported. As a result the primer will flow into the channel and then it gets shaved off when the barrel recoils back and drops down. If it shaves off too much the metal bits foul the firing pin and she misfires.

However - I realize that primer behavior is part of reading pressure signs so I don't want thicker small rifle primers to mask high pressure signs - so - like I said this would be a secondary reason.

My plan would be to take the same powder, same bullet that I have a known, safe load developed. Drop down 10% and work up with the rifle primers, chronographing each step of the ladder and quit when I get velocities similar to my loads developed with small pistol primers.

[tomme boy]

If they are standard cci sr then you should be gtg. I have used them in a bunch of 9mm semi pistols. The cci sr are the same thickness as their sp primers. I also did not have to change my load either. I run a mid range load and do not load any 9mm for my pistols hot. My AR9 I have loaded at max loads to get it to cycle 100%. But they will not chamber in my pistols so I am not worried.

[USSR]

Normally, no problem substituting small rifle primers for small pistol primers, but not the other way around. Worse case scenario would be not reliable ignition due to a weak spring. A revolver would be much more inclined to set them off rather than a pistol.

Don

[beshears]

Small rifle primers are taller than small pistol primers. It can result in slam fire in semiauto weapons.

[Black Jaque Janaviac]

Small rifle primers are taller than small pistol primers. It can result in slam fire in semiauto weapons.

I don't believe this is true. I tested a couple by just pushing some primers into empty cases to see if the hammer would provide enough force to ignite them and they did not protrude from the pockets at all. Well . . . after I popped 'em off they protruded but only because there was no pressure to push the case back to reseat the primer.

[tazman]

Small rifle primers are taller than small pistol primers. It can result in slam fire in semiauto weapons.

Not true. Large Rifle Primers are taller than large pistol primers but small primers, rifle or pistol, are all the same dimensions.

[onelight]

Some load data for the 327 federal calls for small rifle primers. And some calls for small pistol primers.

[Hick]

On one occasion I got mixed up when reloading and put my Winchester small pistol primers in my 223 Rem cases and my Winchester small rifle primers in my 357 Magnum cases. Both worked fine.

[USSR]

Small rifle primers are taller than small pistol primers. It can result in slam fire in semiauto weapons.

Definitely not true.

Don

[la5676]

I'm good for a while longer on sp primer, but did notice the last time I was up at the components shack at the club, there was ZERO sp primers on the shelf, I was considering adding to stock while there getting something else. Shelf loaded with sp magnum primers. Well, I just came home and googled a while, and came across a plethora of threads on various boards (and I'm not too sure one or two of the archived threads were from castboolits) that indicated one could sub sp magnum primers for regular sp primers quite safely in nearly any midrange load. If approaching max grains in listed recipe, avoid use, otherwise, they don't increase pressure that much on lower to midrange loads.

YMMV

[dale2242]

I have used them in my GP100 with heavy loads with no ill effects.
All the rounds performed normally.

[toallmy]

I used up a bunch of old CCI small rifle primers that I had left over from the 80s loading 9mm rounds during the Obama component shortage .