I had a chance to test some imr 7977 today in my 300 weatherby.
Was using weatherby brass, fed 215s and the barnes 175gr lrx bullet.
82.7gr
2958fps, 2956, 2955
83.4gr
2977, 2977, 2980
84.1gr
2998, 2997, 2999
84.8gr
3014, 3014, 3017
85.5gr
3036, 3037, 3034
86.2gr
3083, 3081, 3084
Going to load up a few more in .7gr increases and see where that goes.
Sure is consistent. All groups measured .75-1".
