WC 857 300 WM Load Notes

[Blanco]

Please note that this is purely experimental. Take any and all my information as dangerous and not to be attempted by the inexperienced ! Use at you own risk!!

I ran some WC 857 in my 24" Savage 111 300 WM today ( Lot#48129)
only tested 4 loads and only for speed & pressure check 3rds ea. Hornady brass CCI Mag Primer OAL 3.5 Berger 185 Jugs
75 Gr 2550 FPS
76 Gr 2650 FPS
primers slightly flattened and a soot ring on the neck. shoots 2" low compared to my normal load of 73 Gr R22
Looks like it will need a pretty full case to get good speed with the 185 bullet.

77 Gr 2655
78 Gr 2705
both had slightly flattened primers but extracted easily.
@78 Gr the case is very full, to the bottom of the neck. So 78 Gr. is a slightly compressed load.
I do not think adding powder will gain much more velocity and 2700 fps is not exactly what I would consider great performance.
I think that I will have to go to 200+ Gr bullet to get it to bark.
I did run across something interesting on the 78 Gr loads all 3 shots measured Exactly the same speed 2705 fps. They also grouped really nice.
I would say this powder likes some compression.
This powder reminds me a lot of Hybrid V100. I think it will shine in short cases with a lot of volume and a heavy for caliber bullet and a small caliber opening in relation. like the short magnums. This powder may perform well in .270 Win 243 Win also and maybe a long barrel ?
I have some 212 and 22O Gr Hornady's I will test next.

[cabinarms]

I assume this must be slower than WC 860? for 50 BMG + 20MM?

[Nobade]

Lower number is faster. It is somewhat faster than 860.

[cabinarms]

Lower number is faster. It is somewhat faster than 860.

I missed the (5) in 857 somehow??
when using WC860 in 25-06 the case is filled to top and the crunches the powder down. (70 grains in Win brass + 115 grain bullet) seated to 3.340"
Really the WC857 would be a better alternative and should do well in the 300 WM, would prefer that for 25-06 myself.