This is a FWIW: I gave my H414 to my second son for his 7-08. But it proved no better in his M70 Featherweight than it did in mine. After never giving the accuracy for any bullet tried in mine from 139s to 175s, I did a lot more research and stumbled on the idea (from somewhere that I don't recall) that IMR 4064 might do what I was looking for... It did, and became a kind of miracle powder IN MY RIFLE! I'm going to suggest it to my son.
But before handing it over to my son, I also tried it in my 9.3 x 62 with the 286 Hornady and the 320gr Woodleigh. It gave good accuracy for each but MV wasn't as good as RL-15. I replaced RL-15 with RL-17 and that became my "miracle powder" for the 9.3 x 62. Nothing else has come close!
I mention this because H414, IMR 4350 and RL-17 are supposed to be within the same ball park as to burn rate. NOT SO! I've used enough of all those to know the differences. RL-17 works best when compressed in conjunction with a magnum primer, specifically the WLRM primer. It is a tad slower than H414 (W760), has more energy than IMR 4350 being a double base powder and doesn't change in any significant way with temp changes -- which RL-15 did! As someone here mentioned, H414 (W760) will let you know right away if you've gone too far! RL-17 doesn't have that habit.
So, while BG might be a good substitute for H414, so might RL-17. It's a tad slower than BG, but they are close. Just as H4895 can be compressed significantly for best results in a .458 Win with heavy bullets, so RL-17 works best with heavy bullets in the 9.3 x 62 when compressed and ignited by a magnum primer.
The point being: Experiment with something different, especially with some of the newer powders. IMR 4895 is made in Canada. H4895 is an "extreme powder" made in Australia which I much prefer over the IMR version, unless they've improved it -- likely MD would know about that. There are good substitutes for H414 that might work better, as I discovered for my 7-08.
Bob
www.bigbores.ca
