Using Magnum Primers Instead Of Regular Ones


April 10, 2007, 07:04 AM
I'm in the middle of a batch of 148 Gr HBWC using 3 Gr. of 231. I'm running low on primers and I just noticed I have almost a thousand small magnum primers. I know it's not always a good idea to substitute them but seeing this is such a light load I wonder if it would be a big deal. Your thoughts would be appreciated.

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April 10, 2007, 07:33 AM
some will say that its not a good idea...some will.

I am one of the ones that say its not a bad idea...just do yourself and your pistol a favor and work up the load from might notice less residue in the barrel after range trips...but you might not.

I do this to keep at least one aspect of my reloading supplies "standardized".

Small rifle mag, small pistol mag, and large rifle mag...don't have anything to use large pistol mag for, but Winchester covers that with their large pistol primers...this is a moot point here, though...

As I said, I have done it with 38 spec's and have had no issues, both out of a Rossi SS snubby and my Thompson Contender 10". it up and you should be just fine...eyes open for signs of pressure!


April 10, 2007, 07:54 AM
ditto db:) I sometimes use small rifle primers and have good results. just work it up carefully as with any "non-published load" :uhoh: I'm gonna get it

April 10, 2007, 08:46 AM
Just buy primers 2 or 3 thousand at a time and don't run out. :rolleyes:
They will be fine. Just plan better next time. :)

April 10, 2007, 08:53 AM
As I sit here typing, I have visions of an angel on your right shoulder :) , and a devil on your left shoulder. :evil: Each telling you to do the opposite.

I will simply say, "Better safe than sorry". Do you have family? Children? Do you want them to grow up without a Daddy if something does happen to go horridly wrong?! Or worse yet, are you willing to risk an explosion that leaves you alive, but takes out your eyesight? Do you want to go through all of life unable to see everything that you currently do? Guns aren't toys. They are controlled explosives. Why risk an explosion that goes wrong? But, again, I will simply say, "Better safe than sorry".

April 10, 2007, 10:33 AM
I substituted mag for reg small pistol primers for my 38, and noticed no differance, not in feel, accuracy, or condition of expended brass, showing no signs of overpressure. I also have a habit of never exceeding published numbers, and the published numbers come down almost every year, as the powder companies feel the litigous heat. Soon, 3.3 gr of AA#2 will be called a "hot" load...

April 10, 2007, 10:35 AM
I agree with the work up loads with the different primer advice.

I have actually loaded magnum vs nonmagnum primers in a number of cartridges and can tell you that usually there is no significant difference in pressure or accuracy. In a small volume case, a little change in powder charge or perhaps primers would be more likely to make a difference so proceed with adequate caution. If I were doing it, I would start with the lowest end of the recommended powder charges and work up from there.

Jim Watson
April 10, 2007, 10:51 AM
My PhD friend tried magnum versus standard primers in .38 Special. He graphed the effect and the hot primers gave statistically significant higher velocity with other load conditions the same. It had to come from somewhere, pressures must have been up.

In the small primer .45 ACP NT, I found that a small pistol standard primer gave less velocity than the large pistol standard primer in real .45 ACP, no surprise here. A small pistol magnum usually made up the difference and with some powders gave higher velocity than a large pistol standard.

In 9mm P, I found that a small rifle standard gave higher velocity than small pistol standard, again no surprise. But a small pistol magnum primer gave higher velocity than the small rifle standard.

That is what the fine print in the manuals about "working up" loads is about and is the difference between handloading and the Internet Recipe Hunt.

Chief 101
April 10, 2007, 11:01 AM
You'll be fine in this case and in most unless you are working on the edge of max load. You might have a problem with the guns that shoot the wadcutters as some have a lightened trigger that cannot set off mag primers reliably. Max Load aka Chief ;)

April 10, 2007, 11:01 AM
:) 148 Gr HBWC using 3 Gr. of 231
148 GR. HDY LHBWC* 148 231 .358"* 1.160" 3.5 869 14,200 CUP 4.0 956 15,900 CUP Data copied from Hodgdon

Plenty of leeway for the primer difference. 3.0 is a very light load. That is why I said it would be fine.:)

Everyones point about pressure differences is very valid. Watch out near the top.

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