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 .

[ioon44]

I had the chance to buy some CCI 41 small riffle primers really cheap, I did a test to see if I could them for .45 ACP small primer loads. They shot fine with the same load I use with WSPM out of my 1911's but the Walther PPQ .45 ACP did not like them.

[DonMountain]

Another issue that sometimes pops up is a handgun requiring small rifle primers to keep the protrusion of the firing pin from going through the soft, thin primer cups of typical small pistol primers. My two Webley pistols in 38 S&W "need" small rifle primers to stop this from happening.

[Chill Wills]

The 32-20 and the 25-20 are a case in point. They are rifle cartridges but can use small charges of (often) fast handgun powder. Test and see what works - it is load specific.

[richhodg66]

I and lots of people load small pistol primers in the .22 Hornet, works better than small rifle primers.

Many years ago, I grabbed the wrong box and loaded a batch of .38 Special rounds with small rifle primers, don't remember the brand. Anyway, I figured it out when the S&W Model 10 wouldn't reliably set them off, but put them in the Ruger Security Six and they all went off with no problems.

I've also loaded quite a few large pistol primers for reduced loads in rifle cases, no problems there either.

[fecmech]

During the last shortage (about 15 yrs ago) I bought 5K small rifle primers to use. I chrono'd my fast powder loads (BE,RD,Unique) and found little to no difference in velocity. My magnum loads using 296/H110 had improved extream spreads and slightly better accuracy, 2400 didn't matter either way. I don't worry a bit about them in any safe load.

[Dave W.]

Other than the cups being a littler harder, I have never had problem using small rifle primers in place of small pistol primers.

Small rifle magnum primers will make a difference, so be sure to reduce the load some.

[FLINTNFIRE]

Son in law bought the remington small rifle primers 6 1/2 , told him to use them in his 9mm as they are not for the 223 . I load the 32-20 and told him I would trade him if he wanted , other then that I use the size and style as it is marked

[ACC]

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?

Back in the day when I had a Contender I would use rifle primers in every cartridge. And I had quite a few barrels. Never had any problems but I worked up using the primers I was always use.

ACC

[GBertolet]

I used small rifle primers for years in the 40 S&W 1911, I used for USPSA competition, as added insurance against primer flow into the firing pin hole. The 38 Super users really needed them, for the same reason, as to make major power factor, their pressures were way above SAAMI specs for that cartridge. The dimensions for small pistol and rifle primers are the same. I imagine that the rifle primers have a little more compound in them also. Probably similar to small pistol magnum strength. The small rifle has a thicker cup, which can withstand higher pressures without flowing back into the firing pin hole. That's the advantage for these applications. The only real disadvantage is, you need a good firing pin hit to set them off. Some of the guns with light firing pin strikes might have issues.

With the current run on loading components, we all may have to make due trying different things.

[Black Jaque Janaviac]

I used small rifle primers for years in the 40 S&W 1911, I used for USPSA competition, as added insurance against primer flow into the firing pin hole. The 38 Super users really needed them, for the same reason, as to make major power factor, their pressures were way above SAAMI specs for that cartridge. The dimensions for small pistol and rifle primers are the same. I imagine that the rifle primers have a little more compound in them also. Probably similar to small pistol magnum strength. The small rifle has a thicker cup, which can withstand higher pressures without flowing back into the firing pin hole. That's the advantage for these applications. The only real disadvantage is, you need a good firing pin hit to set them off. Some of the guns with light firing pin strikes might have issues.

With the current run on loading components, we all may have to make due trying different things.

You just discribed my secondary reason for wanting to substitute SR primers. With factory loads, my 9mm will show some effects of primer flowing into the pin hole. But with reloads, it can be more severe to the point of clogging the pin hole with metal shavings.

My question is, if using SR primers makes the problem of primer shaving go away, am I just masking the signs of over pressure?

Part of me thinks the primer flow could be due to over pressure because it doesn't do this as bad with factory loads. Part of me thinks it is not over pressure because I observe this with every load I work up and it happens before I reach max. And the chronograph does not indicate any wild velocity gains at the charges which create the primer problems.

So would SR primers just mask the problem?

[megasupermagnum]

You just discribed my secondary reason for wanting to substitute SR primers. With factory loads, my 9mm will show some effects of primer flowing into the pin hole. But with reloads, it can be more severe to the point of clogging the pin hole with metal shavings.

My question is, if using SR primers makes the problem of primer shaving go away, am I just masking the signs of over pressure?

Part of me thinks the primer flow could be due to over pressure because it doesn't do this as bad with factory loads. Part of me thinks it is not over pressure because I observe this with every load I work up and it happens before I reach max. And the chronograph does not indicate any wild velocity gains at the charges which create the primer problems.

So would SR primers just mask the problem?

Don't put all your faith in the chronograph. I find that more often than not magnum SP or SR primers produced LOWER velocities than the identical load with standard SP primers. Does this also mean the pressures are lower? I don't have any proof that it does or does not, but my guess is that the pressure is similar, even with lower velocities. I'm not talking huge differences, 10-20 fps most of the time.

SR primers do show less flattening or cratering than SP primers, but it does depend on the brand. Federal 100's that flatten right out, might show nothing with CCI 500's. And years ago when I contacted CCI, I was told the 550 and 400 (SPM and SR) are the exact same primer. Winchester SR primers tend to flatten out more than say Federal 205's. As I said, small primers are quite variable by brand.

As long as you are staying close to trusted published data, there is nothing to fear. Primers always have been a poor test of pressure. As long as you stay close to published data, chronograph readings are not wild, and you don't see any crazy signs like loose primer pockets, you will be fine.

[Black Jaque Janaviac]

Don't put all your faith in the chronograph. I find that more often than not magnum SP or SR primers produced LOWER velocities than the identical load with standard SP primers. Does this also mean the pressures are lower? I don't have any proof that it does or does not, but my guess is that the pressure is similar, even with lower velocities. I'm not talking huge differences, 10-20 fps most of the time.

SR primers do show less flattening or cratering than SP primers, but it does depend on the brand. Federal 100's that flatten right out, might show nothing with CCI 500's. And years ago when I contacted CCI, I was told the 550 and 400 (SPM and SR) are the exact same primer. Winchester SR primers tend to flatten out more than say Federal 205's. As I said, small primers are quite variable by brand.

As long as you are staying close to trusted published data, there is nothing to fear. Primers always have been a poor test of pressure. As long as you stay close to published data, chronograph readings are not wild, and you don't see any crazy signs like loose primer pockets, you will be fine.

No I am not putting all my faith in the chronograph. I noted the loads were below max published data, plus I added the bit about velocities. I also could add that although the primers flow into the firing pin hole, they do not appear to flatten around the edges.

[jwhite]

I always load 357's intended for my hand rifle with small rifle primers, mostly because I am trying to working through thousands of Wolf SR primers i got years ago during one of the shortages. They are really hard and lead to misfires in most other rifles but that heavy hammer fall of the handirifle lights em off every time.

[jsizemore]

I used some small pistol magnum primers in my moderate pressure 9mm loads (grabbed the wrong box). There wasn't enough pressure to seal the primer cup to the primer pocket. Plenty enough pressure to fire cut the breech face. Now I got a mess.

I shot plenty of 357 loads with SPMP in my contender back in the day.

[GBertolet]

One thing I failed to mention in my earlier reply, sometimes the firing pin hole in the slide, is much larger than it should be, in relationship to the firing pin diameter. This extra gap increases the possibility and magnitude of primer flowback. Having flowback under these conditions, is not necessiarily an indication of excessive pressure. Small rifle primers are just a workable band-aid for this condition.

jsizemore, I experienced similar issues using WW LP primers in the 45 ACP. The cups are too hard to seal the primer pockets, causing pitting of my breachface. Federal primers, which are softer, never caused this. I have since switched back to Federal primers.

[kevin c]

GBertolet describes a very common and still ongoing practice of using SRP in pistol rounds that need to make major power factor in IPSC and USPA action pistol shooting.

To minimize felt recoil but still make the required velocity for the weight of the bullet, fast burning powders that generate high chamber pressures are commonly used in some divisions. In others, a big charge of a slower powder is used to generate enough gas to make the compensator work efficiently, but in small capacity cases like the 9x19 (which are cheaper). Either way, there can be lots of pressure, so SRP are used to reduce primer smear/flow/piercing.

In my Division, I can use sane loads and standard SPP.