I tried this in my 6.5 SAUM and lost so much velocity that it wasn't usable for me. This was compared to RL26. RL 26 could get me up to 2900 fps with 156 bergers but the rifle likes something in the low 2800s. Winchester HD was never going to make it for me unless I went way over recommended max charge wt. If you want to try it because others have had some success, I would highly recommend you try something less than an 8 lb purchase.
If you lived closer, I would give you 1/2 pound to try because I started with four 1#s of the HD. I'm running H1000 with my 300 WM and 215 Bergers and like that combination. RL26 with the 300 WM with the 215s would be a close second. If you were running lighter bullets RL23 might work but probably not with the 212 ELDX. The HD grouped well for me with the 6.5 SAUM but losing 150 fps for the same group size seemed like a poor trade. I don't currently have an application for the HD so the powder will likely sit on my shelf for an extended time unless I stumble across someone local that wants it.