Power Pistol vs Unique REDUCED Rifle
Have used Lyman loads re: Unique in 458win mag, this worked well even tho recoil (from generally PUBLISHED heavier loads) has never been a significant issue for me ... the way have always gone about things. Don't shoot FULL HOUSE or factory loads though, in 458wm nor 460wby, have no need for ultra high PSI.
As have gotten older with some mild tendonitits in upper arm that managing well, have also used H4198 & H4895 PUBLISHED in 460wby, with 405g/350g .... for great LEVERGUN VELOCITY loads in a 22inch scoped Winchester Mauser. Very ACCURATE, 1750-1950 fps, tho 50-60%ish case fill(PUBLISHED) with no known issues, hangfires, squib etc.
Then got to thinking(for a bit lower velocity in 1500fps or less), would not mind working up 460 wby 405g cast loads using Unique INSTEAD of similiar velocity PUBLISHED loads using Trail Boss (but referencing 416 rigby case capacity). BTW, the rifle twist in this gun stabilizes heavy bullets very well, at the lower velocities so far. Also, use Quickload for estimating PUBLISHED data, not to build loads from direct.
Finally, also thinking that POWER PISTOL might? be better than UNIQUE for reduced loads, it seems to be generally more flexible in its wider range of use.
The thing is, both these powders(Unique&PowPist) are OFF the reservation(to my knowledge in 460wby) PLUS it is such a big case w/ sharper OVERBORE shoulder dims, that allow for more gas pressure build-up etc.
Would not just build loads from reading just anything off the internet either but would like to hear useful thoughts and/or any experience! or Publications/Direction am not aware of? Thanks, Squint.