Small pistol primers

[RonnieDT]

A friend of mine has small pistol. Annum primers but no small pistol primers. Is there an acceptable substitute for 9mm using the smallnpistol magnum primers? For examole, could I subtract 1 grain of powder if I'm using the hotter primers? Jist wondering i have 10k large pistol primers but ZERO small. Id love to trade some large for small, but none of my friends are interested. I figured if I could utilize the small pistol mag primers, I would. After all, im jist shooting paper with them

Thanks in advance!

Ron

[knight0334]

Trading off non versus magnum is generally an okay thing to do.

Magnum primers are for larger quantities of gun powder, or for igniting harder to ignite gun powders. I recommend as you suggest, backing off the powder charge a grain or two, maybe more, then work back up. Magnum primers will provide a hotter flash, which will often burn the powder faster causing a higher pressure. Backing off that charge will help bring things back into balance.

Note: Type of powder will factor. With some powders you may not notice a difference, with others you can go from warm load to unsafe load.

[cephas]

As Knight alludes to, the faster the powder the more you want to take care.
Many do this. Depending on powder I knock off 5-10% and work back up.

[243winxb]

I use WSPM for 9mm Luger with Speer starting loads with 125 gr cast bullets. No problems. https://www.speer.com/reloading/handgun-data.html