Re: wc-860 & wc-872??
872 is much slower then 860.
860 has the burn rate (some lots) of the old H4831. 872 has the burn rate of the 5010 powders.
872 is a great powder for cold weather longrange hunting and is not as hard on barrels as 5010 or 50 BMG seems to be.
The accuracy seems to be excellent with the 872 if it's not 85 or 90 degrees out.
Many of my longrange friends and I have for many years use it in most all our bigger longrange cases starting with the 6.5/300 Weatherby and going up with all the calibers I/we use.
In the 300 Tomahawk (imp 300 RUM) and using 240 gr bullets in a 34" barrel, I have churned up 3225 FPS using 872.
When it's hot out, we just load it down 2 or 3 grains and the flyers seem to be non existant.
WC-872 has won relays at Williamsport 1000 yard matches but, I don't think a year end aggregate has been won with it.
It's a great hunting powder for large cases though and the price is right. Usually about $5.00 or $6.00 per pound now.