Small pistol primers: Magnum vs Regular.

[Dubious_Beans]

I bought some "magnum" primers from the local shop cuz that's all they had.
Any words of wisdom for using magnum primers instead of regular primers for 9mm loads? (Federal #200 vs Federal #100)

Thanks!

[Alien62]

I bought some "magnum" primers from the local shop cuz that's all they had.
Any words of wisdom for using magnum primers instead of regular primers for 9mm loads? (Federal #200 vs Federal #100)

Thanks!

As a rule I've heard if you cut back .5 - 1.0 grains on your regular loads you should be fine. start low and work up.

[ireload]

Similar to what Alien stated, I use the minimum charge listed then work my way up in .3 increment.

[Divernhunter]

I use mag primers all the time. One test in Handloader mag showed same loads to be more accurate with mag primers vrs rsg primers. "I" have never had a problem with the mag primers but if you are at max you may want to back off alittle then work back to max. Do not make it a major point to worry about.

[Cowboy T]

+1 to all the above. I've done it with my powder-puff .38 Spl LSWC load. No noticeable difference at these lower pressures.

[PoofNoEyebrows]

Agree with everything above as well. I usually only use them when I want a slightly thicker cup to help prevent slam fires.

[Dubious_Beans]

Thanks to everyone for their input about magnum primers. I've been assured it's OK from other sources but wanted to run it by the Calguns crew just to make sure I can feel all warm and fuzzy about it....
So far I've fired 250+ rounds of "homebrew" ammo using magnum primers and haven't blown my gun up yet, so I'm starting to feel more confident.

So... assuming "regular" and "magnum" primers are the same price, is there an advantage to one or the other for assembling 9mm cartridges?

Thanks much!

D.Beans

[PoofNoEyebrows]

An easy check you can do to keep an eye on pressure is to look at the primers after you fore some rounds. If it looks really flat with a sharp edge at the shoulder you might want to think about reducing a tad.

[huckberry668]

Be careful using mag primers for regular calibers/loads. I tried to develop a load for 40SW with Mag primers and they gave terrible accuracy no matter how much I reduce the powder. Accuracy was good (2.5" at 25 yards benched) with the same powder using regular primers.

I also tried using Mag rifle primers in a 308 match load of mine and it throws 1 or 2 shots off out of 5-shot groups. Same load with regular primers shoot tight groups with no fliers.

There is no need for mag primer unless the caliber, powder and amount of powder require it. However, there is no reason not to use it if it doesn't affect accuracy or safety.