Consistent ES and SD

[DoneNOut]

Todays load development. First pic is 16 shots to find my charge. 2-shots each in .4 increments over 2.8 grain.
Second pic Settled on 56.78 H4350. 6-shot data/ 3022 fps SD 1.2-ES 4 .32 group. View attachment 447801
SD 1.2

Yeah, you get it. Impressive load development and groups. 5 shots is my minimum count for group measuring, final test is 10-12 shot groups. I also shoot 5 shot groups over time and super impose the groups to get up to 20-30 shot group size.

 

[338 dude]

I never really understand the need for Mag Primers in cases that hold less or about 75 grains of powder or very close to that. Above that then I would think mag primers would come into play. I don't have any rifles chamber for the larger powder charges. My biggest rifle is a 338WM. I have several other belted mag but in smaller calibers.
The other is I have held my ranges down to 500yds.

Don't know where I heard this, but a rule of thumb was 60 grains and above magnum primers

 

[DoneNOut]

Don't know where I heard this, but a rule of thumb was 60 grains and above magnum primers

Or magnums for large rifle if that's all you can get!