Small pistol magnum primers

[Andrew Quigley]

I was needing some small pistol primers the other day and came across a deal on 3000 small pistol magnum primers. Was wondering if I need to reduce my loads any when I use these? I don't load to the max on any of my loads, 45 colt,45acp, 40 s&w, 9mm, 38spl and 380. Most are all 1/10 th of a grain under max. Thanks for any info.

[trying2learn]

I would bet that everyone on here will agree for the most part that you need to work your loads up from the start again. Since you are changing primers. However I have heard the guy at my lgs tell many a person to reduce by 10 percent and it would be fine. I don't agree with him j think if you are changing to a magnum primer you don't know for sure how the powd er will respond. So be safe and start at the bottom better to work back up then lose a gun, a hand or anything else. More will probably chim in and be more spot on.

[Mlcompound]

I have been using them on 38 special with good results. I do recommend starting a new load workup just to be safe. The cups are harder and won't show signs of high pressure as well so be safe.

Sent with my Evo 4g from Tapatalk.

[fecmech]

Back during the last primer shortage I was unable to get SP primers but was able to get small rifle primers. Used them in all my .38 spl loads and chrono data was pretty much identical to standard sp loads. Only real difference I saw was that with 296 and H110 in max magnum loads ballistics were much more uniform and accuracy improved. I now use SR primers in all my .357 mag loads.

[bobthenailer]

i once tried FED SR in a 357 mag load i had worked up with Fed SPM accuracy was the same at 100 yards

[StratsMan]

If you're concerned about pressure, send those magnum primers to me... I'll test 'em....

I'd have no qualms about shooting mag primers with a powder that doesn't require one, but I wouldn't shoot 0.1 grains under the max load... Start closer to the bottom of the powder makers range, and work up until you get the accuracy that you want without indications of excessive pressure...

And I think the 40 S&W likes magnum primers anyway, depending on the powder....

[Bwana]

I was needing some small pistol primers the other day and came across a deal on 3000 small pistol magnum primers. Was wondering if I need to reduce my loads any when I use these? I don't load to the max on any of my loads, 45 colt,45acp, 40 s&w, 9mm, 38spl and 380. Most are all 1/10 th of a grain under max. Thanks for any info.

If you are loading, "Most are all 1/10 th of a grain under max.", then you don't know about working up a load. You are using information that varies from your conditions and is only to be used as a guide while working up the load for your gun and components. If you were using loads that were at the starting end of the "load" spectrum then I would reccommend dropping one half grain when substituting a mag primer for a regular one. but, that's not what you want to do and therefore no one can safely give you an amount that will result in a load which will be safe without you starting out low and working up.

[Hardcast416taylor]

What powders would those be that the .40 S&W likes with mag primers?Robert

[Andrew Quigley]

I started out on the low end with all of my loads but as it turns out 1/10 under works well enuff in my pistols. I'm not looking for that one hole cluster at 25yrds. I shoot Idpa so power factor comes into play for me. I also shoot SASS with 4 different 38's so I'm not going to find a seperate load for each gun. I'll just work up from the bottom again. Thought someone else might have done this and was just curious.

[Spawn-Inc]

you can't use magnum primers, it's very dangerous! just leave them on the shelves and i will deal with them.

i switch them without issue, but none (outside of my 357, 500) of my loads are at max.

[boltons75]

Picked up a box for my 40, and went through the 1000 without issue.

[30calflash]

I'm thinking about the scenario 180 degrees off.
How do you think that mag SP primers would work in a 30 M1 carbine? IMR 4227 or W296 for powder? Not like a 223, similar pressure to a 357 in general. Any thoughts or comments/

[wv109323]

Winchester does not recommend that WW296 be loaded down. I would be hesitant at starting a max. loads with WW296. If pressure is similar to a .357 then you may get away with it with the IMR 4227. The other thing to worry about is the stronger firing mechanism of a rifle over a pistol. The rifle may drive the firing pin through the thinner pistol primer. I would try just a primed case to observe what the firing pin does to the primer then work up to a load.

[shotman4]

you may get a Big surprise using pistol primers in a M1 carbine. that is a free float firing pin.

[dnotarianni]

Been using reg and mag SP in 38s and 9mm without a problem. Using the same powder charge I see a 30 FPS diference between reg and mag. Drop .2 or .3 gr and worry about nothing.

Dave

[BCRider]

Just a note about "pressure signs". Keep in mind that you'll only see the warning signs of over pressure in cartridges that are spec'ed for operating up in the mid to higher 30's. So if you were to see pressure signs in a .38Spl it means that you crossed out of the pressure limits of this round WAY back and are up around the max pressures found in max .357Mag rounds. The same goes for any pistol cartridge where the maximum SAMMI pressure is anything under 30K psi.

The big thing about rifle and magnum primers is that the cups are of a heavier gauge metal. So it takes a harder hit to set them off. On handguns where folks like me have replaced the mainsprings with lighter ones to reduce the trigger pull this can easily lead to failure to fire.

[Bwana]

"The big thing about rifle and magnum primers is that the cups are of a heavier gauge metal."

The only cups that are thicker/harder than their respective counterparts are Rem 7 1/2, CCI41, CCI450. There are some differences between manufacturers but not within their product lines besides what I've listed. This regards US made primers.

[km101]

I'm thinking about the scenario 180 degrees off.
How do you think that mag SP primers would work in a 30 M1 carbine? IMR 4227 or W296 for powder? Not like a 223, similar pressure to a 357 in general. Any thoughts or comments/

I wouldnt do that. The .30 carbine has a floating firing pin. You could get a punctured primer.

[MR835]

I Use SMR & SMP Primers in my 30 carbine coustom loads and the work fine. I worked up all the loads from the lower end up.

SAFE SHOOTING ALWAYS

MR835 IS GONE

[ROGER4314]

I think substituting primers depends a lot on what data that you're using. I have almost 20 loading data manuals and in comparing them, found many discrepancies. The Lyman 49 is the most conservative manual while others like the Lee manual run closer to the upper end. Charge data in the Lyman is so conservative that I doubt there would be any issues with a primer switch.

I don't switch primers as I don't feel comfortable with it. But the reality is this.....In the current market, standard primers are hard to find but I noticed that Magnum primers sell much slower and stay in stock. You gotta do what ya gotta do. That is a viable source of primers if you have no other options.

Incidentally, I got out of reloading for some years and when I got back into it, found that a lot of my usual magnum loads that needed magnum primers before, now don't require them. A lot has changed in our loading data over the last 10 years or so!

Flash

[opos]

I wouldnt do that. The .30 carbine has a floating firing pin. You could get a punctured primer.

I shoot a 30 carbine Ruger Blackhawk so the floating firing pin situation would not be an issue...would it then be reasonable to load the 30 carbine (I shoot moderate loads of 2400) with a small pistol primer? Got lots of them and very few small rifle primers left...thanks for any input on this.
opos

[44man]

I have tested many primers and the SP, SP mag and SR show just little differences. Only so much room for the compound.
Yes, some have thicker metal. But the important thing is a difference in primer pressures and although low for small primers, the safe thing is to work up.
I have never punctured a primer but a soft, thin cup can slam fire with a floating pin. The worst is the AK's that need very hard cups.
The only real change I have found is a difference in accuracy between primers.

[leeggen]

If you get on the net and check, the pistol primers ,whether magnum or not, are built with thinner primer case metal sense pistol preasures are 16,000psi or less. Rifle primers are buith with thicker case to withstand high presures in the 30,000psi and up. Useing small rifle primers in pistols can be ok,BUT small pistol primers in rifles,remember high pressure, will or can result in blown out pimers. ALWAYS remember the extreme preasure difference between pistols and rifles. Look at the load data pressure difference in the manauls and it will make sense.
CD