Re: Daryl Cassel help
I would and do use the H-870 and WC872 (Just a tad slower then H870) which is within 2 grains of powder out to 100 grains total. In other words you can use 2 grains of powder MORE then the H870 at 100 grains and be safe. For all intent and purpose, both powders are very near the same.
For my hunting applications it has "always" been H870 and WC872.
Yes, both powders being highly graphited, will give you longer barrel wear especially in the big mags.
All the testing on the 300 Tomahawk (Improved 300 RUM) was done with WC872 powder. I tested 200, 220 and 240 gr Sierra MK. and other bullets also.
You will have to watch loading for the faster twist of your barrel. You will not be able to use as much powder safely, as I did in my 10 twist.
I think you stated you have an 8 twist.
Hope that helps