Std vs Mag Pri - 40 S&W

[Steve]

These loads lead the barrel and accuracy suffers, but the results on primer comparison is interesting.
Pistol = S&W M&P 40 full size, 4.25" barrel. 180 gr cast bullet.

CCI 550 primer, Ave 972 fps, ES 40, SD 10.
CCI 500 primer, Ave 959 fps, ES 57, SD 15.

Interesting,,, 3.25" barrel of compact M&P shoots the std primer load well at about 30 fps less.

Going to try to reduce load to 920 fps in full size with each primer. This will keep me at major power factor for ipsic matches, plus keep felt recoil near the same as my carry round.

My conclusion, on my M&P pistols I'm not going to be very worried about differences primers make.

I didn't list all load data because the powder is not manufactured any more. I'm told 700x burns about the same as Rex 2. I'll have to find out in about 8,000 more rounds.

[Maximumbob54]

I didn't care one bit for the way 700X measured out. Very erratic. It makes Unique look like it flows well. I would try Power Pistol or better yet one of the Accurate powders like #5 or #7.

And you might want to look into coated bullets. Try SNS casting for the Hi-Tek coated bullets or if you cast them yourself then powder coating in cheap gloss red from Harbor Freight is very easy.

[Steve]

I didn't care one bit for the way 700X measured out. Very erratic. It makes Unique look like it flows well. I would try Power Pistol or better yet one of the Accurate powders like #5 or #7.

And you might want to look into coated bullets. Try SNS casting for the Hi-Tek coated bullets or if you cast them yourself then powder coating in cheap gloss red from Harbor Freight is very easy.

All good advice. So many things to try, it's all fun.
I have used accurate #5, worked good but had poor case life. #7 made me clean my pistol more often..... being as lazy as I am that kind of shot down the #7.