Small pistol magnum primers in lieu of small pistol primers. Thoughts? Opinions?

[sixGuns]

So, I finally got in my new Dillon 9mm dies (15 months!). Loaded up 200 9mm with small pistol magnum as that's all I have on hand at the moment. I've read some stuff that it's totally fine and likely just a 50 fps increase on whatever a specific load data calls for. All 200 went bang and I had no problems, signs of overpressure or weird shooting related anomalies. I'm just curious as to what others have did/done/experienced with this.

I was using some Alliant Bullseye I had leftover per their published website recipe. Their max was 4.4 grains. I went with 3.7 grains as a start with a 124 grain FMJ with a COL at 1.155".

I still have 1200 more Federal small pistol magnum primers.

I guess I'm curious how much (what %) I should download considered this primer type for "full power" 9mm...

 

[nucular]

your 50fps guess is probably pretty close. I haven't noticed much if any difference but I'm sure you are fine at 3.7. If you want to go hotter, just do a ladder up to max and see how each round looks. I usually do my ladders in .2 grain increments.

With that said, I would save your magnums for when you actually need them especially since SPP seems to be pretty easy to find right now.