Primer question

[Blake_G49]

A quick question for the brain trust - I have some pretty significant handloading experience (rifle and handgun), and to my best recollection I have never used a Magnum primer in anything. While going over my primer stocks I notice that I'm under 5K for small and large pistol but I have 7K of small pistol magnum and 4K of large pistol magnum (I think from some long-forgotten trade).

My question is this - keeping in mind that I know I will have to go back to the baseline and develop any load from scratch and not just do a straight swap of magnum for standard primers - how much "real" difference is there between standard and magnum primers in handguns??


many thanks in advance

blake

[Der Gebirgsjager]

That's kind of a hard one to answer precisely, because there are too many variables. Which handgun cartridge are we talking about, and what load? I can only answer from limited experience in exchanging magnum for regular primers and give you a generality that in my opinion the magnum primers have a value of about a 10% pressure increase. Back when primers were short the last time a large gun club I belonged to was able to continue getting the magnum primers for several months after the regular primer supply dried up. There were regular action pistol competitions, and some who competed with 1911 pistols eventually found cracks in their pistol frames. On the other hand, those who used revolvers noticed no ill effects. So, there's another variable-- the gun in which the loads are to be used. Your statement that you'll start low and work up to a satisfactory load is a wise one.

[Der Gebirgsjager]

By the way, I belatedly saw that it's your first post. Welcome to the forum! :grin:

[Blake_G49]

By the way, I belatedly saw that it's your first post. Welcome to the forum! :grin:

Thanks so much - I was a member years back and posted then, but my profile disappeared (probably from lack of use) and this one is the first for the "new me". The boys are grown and moved out, I'm getting closer to retirement and just built a new shop so the time for old hobbies is there again.

blake

[quilbilly]

I haven't found there to be that much difference between mag and regular small pistol and mag and regular rifle. On the other hand, I shoot Red Dot powder in several of my light rifle loads (222, 223, 270, and 308) and I get more complete combustion using the magnum primers. Welcome to our forum!

[tazman]

If you are loading maximum loads you need to back down and work up again. If you are loading midrange or light loads, you probably wouldn't notice any difference.
A couple of times, I had to use magnum primers because I ran out of standard and when I shot the new loads, they actually grouped better than standard primers.

[Blake_G49]

Thanks gents - about what I figured. I'm shooting moderate loads with TiteGroup in .38 Special, .45 ACP, .44 Special/Mag and .45 Colt... I'm pretty sure the process will move forward without incident...


blake

[Norske]

Elmer Keith tried magnum pistol primers when he experimented with a 41 Magnum. He wrote the hotter primer required a 10% reduction in powder charge. Stick with whatever primer is mentioned in your loading manual for that cartridge. Those loads have been pressure tested.

[charlie b]

When learning about different primers someone posted information from research they had done. One of the more interesting things they learned was that CCI small pistol magnum primers were the same as their small rifle primers. Same cup thickness, same chemical content.

For loading the magnum primers do have a bit more power to them so it does take a slightly different load.

[Rex]

I'm short on primers and found some really old Winchester small rifle primers in the shed, loaded them in a .38 special case with 5 grains Unique and a 150 cast bullet. Shot fine,

[Targa]

I can’t tell a difference and now just I just use magnum primers for everything.

[Ozark mike]

I can’t tell a difference and now just I just use magnum primers for everything.

You may get better results if you use standard primers with easy to light powders. Small cases you could get bullet jump befor the powder takes off therefore hurting accuracy just my cent and a half

[Larry Gibson]

As Der Gebirgsjager says; just too many variables for a "rule of thumb"........

If switching to magnum primers then drop the charge 10% and work back up. A chronograph is a good friend here as simply work up to the same velocity as was had with the standard primers.

[Hick]

I have a Ruger 357 Magnum revolver and a Henry rifle in 357 Magnum-- but I've had trouble locally finding magnum small pistol primers. So I did testing with the Ruger to see how much difference the primer makes. Using Winchester small pistol primers with 150-160 grain bullets magnum primers gave me about 50 fps faster. With lighter bullets (down to 125 grain) I get up to 100 fps faster with magnum primers. but-- no accuracy differences. Because of this I use only standard primers in the revolver and save the magnums for the rifle.

[dale2242]

I tried a small experiment about standard vs magnum primers in 45ACP.
Both were CCI pistol primers.
10 rounds of each load was fired through 3 different 45s.
The loads were all the same except the primers. Brass, powder, powder charge and bullets.
I don`t recall the brand of brass. 5 gr. 700X, 200 gr 452460 bullet cast from #2 alloy, 50/50 lube.
Average velocity was 20 fps faster with magnum primers and no difference in accuracy.
This is by no means a scientific experiment.
Your results may vary.

[Cosmic_Charlie]

Thanks gents - about what I figured. I'm shooting moderate loads with TiteGroup in .38 Special, .45 ACP, .44 Special/Mag and .45 Colt... I'm pretty sure the process will move forward without incident...


blake

I just recently picked up a thousand Federal LP Magnum primers because that was all that was left. I am loading moderate charges of Unique in .44 spl. and .44 mag, 7 and 9 grains respectively with 240 grain boolits. I don't think I will notice a difference.

[charlie b]

On another thread/forum there was a good write up about primers, SP, LP, SR, LR and magnums. One thing I didn't know was that for CCI their SP magnum primers were identical to their SR primers. Same amount of 'powder', same thickness of cup. The thickness of SP primer cups varied a little between mfgs but was thinner than the SP magnum and SR primers. Same for LP, LP magnum and LR.

As stated before, if you use magnum primers just back down the load a little, or know that you are going to increase your pressure and velocity a bit. I would not use them for light loads.

[zipdog]

Does anyone know if CCI magnum LP primers can be used in lieu of LR primers? I need to load some 6.5 Creedmore and have only a few CCI #350.

[yovinny]

Does anyone know if CCI magnum LP primers can be used in lieu of LR primers? I need to load some 6.5 Creedmore and have only a few CCI #350.

No,, different heights and cup material thickness..
LP primers are not built for rifle pressures.