Splat,
There was a day when it was hard to find a powder that was to slow for the 264. With some of the slowest it is possible now. However there are only a half handful at that end of the chart.
That said 4831 is not a slow powder in the 264, usable but at the fast end of the 264 usable range. I have found good loads with RL-25 and Retumbo. 95 grain Vmax with RL-25 (coyotes do not like that load) And 130 grain Scirocco II with 67 grains of Retumbo (took a big bull elk with this load this year).
I tried some US-869 with 130 grain bullets and got poor results I am thinking that it is too slow???? at least for the 130s????
Stay with slow powders from 4831 to us-869 and you will find some thing that will get the job done.
8mmwapiti
