I've never seen a triple shock in .45 calibre. I know they had a 300gr."X" for the .45/70.
I personally prefer to shoot heavy cast bullets in my .458, but do like the 350 Barnes"X" & 400gr. Spitzer. I do wish they still produced the .049" jacketed 400's, though.
: Solid copper bullets do create more pressure than typical jacketed lead core bullets. Trophy bondeds and Barnes "X" come into tis category. The design of the triple shock reduces pressure and should allow loading to typical weight velocities.
: Manuals almost always disagree, one to the next as they sue different barrels which produce different pressure, one to the next. In some calibres, Barnes data exceeds most or all other printed data. For instance, chekc out the 7mm Mauser an 6.5x55 data -yet they were developed with solid copper bullets, not solft jacketed lead ones.
; I would expect 1,750fps should be attainable in a Springfield, 2,100fps in a Marlin, and 2,300fps in a Ruger #1, all in .45/70 - all using a 300gr. "X" or T.S. bullet.
: For all of these ctgs, I'd prefer a 350gr. Hornady, except perhaps the Ruger, but the 350 Hornady RN worked well for me on moose driven at 2,270fps from my Mauser.458 2" - no breakup and amazing penetration through bones, then exiting.