Small Pistol vs Small Rifle Primers

[guns_and_labs]

Are small pistol and small rifle primers interchangeable for .40S&W?

Is there likely to be a velocity or std dev change moving from one to the other?

[Pat Miles]

Small rifle and small pistol primers are interchangeable. Small rifle primers will add several FPS to your velocity thus a tad to your power factor.

CYa,

Pat

[GrumpyOne]

Small rifle and small pistol primers are interchangeable. Small rifle primers will add several FPS to your velocity thus a tad to your power factor.

CYa,

Pat

While they are interchangeable size wise, small rifle have a harder cup and may not seal the primer cup of the case completely, leading to breach face erosion in the long term. It would all depend on the pressure you are running in your 40.

[Pezco]

Yes, you can use both but as mentioned above the primer cup tends to be a tad harder on the SR primers. I have research the velocity difference between SR and SP for a year now and have found about a 35 - 45 fps gain when going to the SR primers. These test took place with my 5" limited SV and my Bedell Shorty Open guns and CED chrono.

[G-ManBart]

Yes, you can use both but as mentioned above the primer cup tends to be a tad harder on the SR primers. I have research the velocity difference between SR and SP for a year now and have found about a 35 - 45 fps gain when going to the SR primers. These test took place with my 5" limited SV and my Bedell Shorty Open guns and CED chrono.

Wow, that's a much larger spread than I've seen in my guns. It made less difference with N320 (almost none at all) as it did N105. It also depends on the exact primer chosen as they're all different from one manufacturer to the next. Fed SPM were actually 2PF higher than Wolf SR

[M109R]

SRP are to hard to dent with a Glock so try to stay away from them. My findings is they are even harder than Wolf SP.

[pjb45]

I use both types all the time. I have keep my chrono records for years now. I see very little velocity difference between the two. I have chrono'd in both Nowlin and Kart barrels.

I have pretty light triggers in both guns -- mainspring is pretty light --- I have not had any light primer strikes comparing SM v. SR v. SPM either.

I had some light primer strikes in 9mm with Wolf primers in my custom BHP which I thought was strange since my Springer Precision XD ran them ok.

[Sgt Smith]

In the past, I've only used the small rifle primers in .38 super loads to prevent pierced primers with hot loads (175-180 power factor). I agree negligible difference in fps with most powders.

Loaded a couple of thousand .40 with the small rifle primers when I couldn't get small pistol last year. No issues.

[major9]

I have developed loads and loaded all my small primer calibers (minor 9, major9, 38SC, 40) with SRP.

All guns are 2011 based, or AR 9mm in the case of minor 9.

No issues, and no inventory maintenance of SPP.

I did find a brick of SPP dated 1994.

I'll probably go make minor 9 play ammo.

[JohnGaultsGun]

Small rifle primers are definitely harder than small pistol. Not to bad when you're shooting a 1911 type pistol. On striker fired pistols (read Glocks in particular) you will have lots of problems. More so if you have lighted the trigger pull by most means.

[blaster113]

I run rifle primers exclusively in my .40 Edge. I like the extra few FPS that the rifle primers give, plus they are all that I've been able to get my hands on recently. After several thousand rounds, I've had no issues with breach face erosion. I tried Federal, CCI, and Magtech small rifle, the Magtech seems to have a much harder cup than regular SP and the cup is barely dented when fired in my gun. With a striker fired pistol like a Glock or an XD, I'd stick with regular SP.

Edited May 21, 2010 by SIG shooter

[dillon]

If you substitute small rifle for small pistol primers, always reduce the load to starting level and work back up. We recently had a customer blow up a .40 pistol simply by changing primers.He was using a maximum load of Titegroup, and Hodgdon confirmed that switching to the small rifle primer was sufficient to cause pressures to exceed maximum pressures.

[G-ManBart]

We recently had a customer blow up a .40 pistol simply by changing primers.He was using a maximum load of Titegroup, and Hodgdon confirmed that switching to the small rifle primer was sufficient to cause pressures to exceed maximum pressures.

Sorry, no offense, but I don't buy that at all. Sure, if you're right at max and switch primers it's enough to go over the maximum, but nowhere near what you'd need to "blow up" the gun. I've compared quite a few small pistol to small rifle loads, in more than one cartridge (to include .40) with no other changes, loaded sequentially, and it didn't bump up the velocity more than 10-25fps....you'd need waaay more than that to break something.

A double charge of Titegroup would do the trick. Did you ask what press the ammo was loaded on and if it had a powder level safety?

Edit to add: I'm not saying that it isn't a good idea to drop down and work back up.

Edited May 22, 2010 by G-ManBart

[GrumpyOne]

If you substitute small rifle for small pistol primers, always reduce the load to starting level and work back up. We recently had a customer blow up a .40 pistol simply by changing primers.He was using a maximum load of Titegroup, and Hodgdon confirmed that switching to the small rifle primer was sufficient to cause pressures to exceed maximum pressures.

I can't see where the pressure generated by a rifle primer could be enough to "blow up" a gun. If they were on the ragged edge of blowing it up already, then maybe, but they would be seeing massive pressure signs, primer flow, bulged cases, excessive recoil, etc. Usually, a gun is proofed to what, twice the normal pressure associated with the round in question? If so, then in no way did a primer cause the spike in pressure to blow up the gun. More than likely a double charge.

[G-ManBart]

Usually, a gun is proofed to what, twice the normal pressure associated with the round in question? If so, then in no way did a primer cause the spike in pressure to blow up the gun. More than likely a double charge.

It depends on whether it's a C.I.P. country or not, but for pistols, I'm pretty sure it's 30% over max pressure. So, for .40S&W the C.I.P. max is 32,633psi, making the proof load 42,423psi. SAAMI uses 35,000psi as a max, so a proof load for that would be 45,500psi. If those won't blow up the gun, I'm with you...it's going to take more than a different primer to get there.

The other possibility is bullet setback. Combine a fast powder, with a heavy bullet and insufficient bullet pull (neck tension) and you can get up over proof loads. Could just be it was coincidental to the primer change. R,

[CenTX]

SRP are to hard to dent with a Glock so try to stay away from them. My findings is they are even harder than Wolf SP.

Have not tried them in my Glock, but My M&P Pro is shooting Wolf SR without any problems.

[GrumpyOne]

Usually, a gun is proofed to what, twice the normal pressure associated with the round in question? If so, then in no way did a primer cause the spike in pressure to blow up the gun. More than likely a double charge.

It depends on whether it's a C.I.P. country or not, but for pistols, I'm pretty sure it's 30% over max pressure. So, for .40S&W the C.I.P. max is 32,633psi, making the proof load 42,423psi. SAAMI uses 35,000psi as a max, so a proof load for that would be 45,500psi. If those won't blow up the gun, I'm with you...it's going to take more than a different primer to get there.

The other possibility is bullet setback. Combine a fast powder, with a heavy bullet and insufficient bullet pull (neck tension) and you can get up over proof loads. Could just be it was coincidental to the primer change. R,

So yeah, at any rate, it wasn't the primer at fault for blowing up the pistol, unless he was at somewhere around 45,000psi anyway. You and I both know that the "proof" load is just that, that it won't blow up any gun at that pressure, but most will go well beyond that before blowing chunks.

[CocoBolo]

I've shot titegroup in a 40 and was pushing 190pf and used rifle and pistol primers in that load, but then I had an sti bull barrel and no go KaBOOM! The velocity diff was 10fps. This load was for Hog Hunting not uspsa. I have since switched to universal clays for more velocity and a 18# recoil spring. I have split some brass and blown the top off a few.

Edited May 23, 2010 by CocoBolo

[GrumpyOne]

I've shot titegroup in a 40 and was pushing 190pf and used rifle and pistol primers in that load, but then I had an sti bull barrel and no go KaBOOM! The velocity diff was 10fps. This load was for Hog Hunting not uspsa. I have since switched to universal clays for more velocity and a 18# recoil spring. I have split some brass and blown the top off a few.

But, if I'm understanding you correctly Coco, the gun didn't kaboom, even with those loads, right? So, do you think it was the primer splitting the brass and blowing the top off the few?

[Bongo Boy]

Guns and legends. Jeeeeez. May God Bless the cowboy in us all, facts be damned.

Edited May 27, 2010 by Bongo Boy