H-414 was a run of ball powder that Hodgdon purchased from St Marks in Florida. Roy in Idaho is right. At the time Bruce Hodgdon sought a competitor to then Olin owned "Winchester" trademarked ball powder. He just bought a batch from St Marks (which then was owned by Olin) but now is independent. Now Hodgdon owns the "Winchester" license and H-414 is redundant.
The data for H-414 is old. It probably is not as good as published. At one time handloaders did not have chronographs. Ball powders were often overrated. I remember the fastest load in the Hodgdon book for the .264 Winchester Magnum with 140 and 120 gr bullets was with H-870 (surplus 20mm cannon powder). The book said 76 gr of this St Marks ball powder would produce 3200 fps. I found you could compress as much H-870 as you could fit in the case. I bulged the cases, popped primers and had the bullets slowly back out of the case but could never get to 3000 fps. 29 and change was as fast as I got. I even tried 1.5 gr of Red Dot over the primer trying to get the ball powder to burn in the barrel. Even velocity with 160 gr round nose was greatly below advertised.
Hodgdon H-450 was the ball attempt to get to IMR 4831 burn rate (50 cal machine gun) It was never as fast as advertised for me. It was erratic and not very accurate.
In the .270 WSM, I like MagPro for speed. I can get 140 gr Accubonds or 140 VLD Bergers to 3300 fps with MagPro. Zoom. I have several 300 yard groups under two inches. There may be more accurate choices but I will tolerate the accuracy of MagPro. I have tried R-25, 4000MR, VV N-560, Win 780, Retumbo, Ramshot Magnum and IMR 7828SC, MagPro is faster with the same or less pressure.