I've been shooting the .257R. I had read that the Roberts often performs best with 100 gr. bullets. I tried the 100 gr NPT and it shot OK, around an inch or better. The 117 SST and 115 NPT were pretty good.
The winner was the 115 NBT. With .02" jump and at around 2,900 fps, two loads were stand outs:
115 NBT, 44 gr. H-4350, three shot group, .357"
115 NBT, 45 gr. H-414, three into .68".
I'm going to try more of the H-4350 load, clock it with 5 shot groups.
I like this gun. It will bust some WT's this Fall, maybe an unlucky hog or two.
DF
Those 4350 loads are quite a bit stouter than what Nosler calls max. How did you arrive at that charge?
I'll get you the specific source when I get home after work.
Generally, I've read articles and studied data. One article showed groups shrinking as loads were increased to +P levels and that seems to be the case here. As you know, most published .257R data is moderate pressure. With a strong action, +P loads are safe and accurate. I have no problems exceeding 45K psi with good brass and "three rings of steel"...
It seems to work, brass showing no sign of excessive pressure.
DF
