Picked up a pound of superformance powde the other day and decided to see if it is really a superformance powder. I have a good load worked up using IMR 4831 and the 168 gr barnes xlc moly bullets, I am getting 3114 fps with 70.2 gr, I figured that superformance would kick it's butt. Being that the barnes xlc's can be loaded a bit higher I started with higher charges, I have listed the results below, very dissapointing.
70 gr 2923
71 gr 3016
71.5 gr 3044
3053
72 gr 3058
3023
72.5 gr 3079
3072
73 gr 3108
3144
73.5 gr 3167 stiff bolt lift
3159 stiff bolt lift
3152 stiff bolt lift
I used winchester cases and winchester magnum primers, the last six rounds were fired with once fired cases, I have noticed that the winchester primers are very soft compared to CCi primers, even the starting load showed flat primers, the last three rounds the primers were as flat as a pancake. Loading data that I have from Hodgdon shows 72 gr produces 3273 fps with a nosler 165 gr partition. The barnes xlc bullets have always gotten me an extra 100 or more fps with a few more grains of powder without any signs of pressure. I plan trying this powder with the 165 ttsx, only thing that I can think of is that it was 38 degrees and maybe this powder does not slick bullets with slow powder in cold temps. If anyone out there has any advice or some experience with this powder I could appreciate some help.
............If I may interject.
The results you are getting with your rifle, won`t be the same as in other 300 WSMs including those barrels which Hodgdon tested.
In your particular rifle, Superformance apparently doesn`t offer hardly any velocity advantages, whereas in other rifles it will.
Variations with velocities given the same cartridges, powder, bullets, charges, OALs and barrel lengths, is just a ballistic normality and fact of life.
Take what you can get and live with what results you do get.
If you`ve tried RL17 and have gotten great results stick with it. In your rifle Superformance may not offer additional velocity advantages.
