Dr. A
"I would like to try Lyman's Gould bullet at 1600 to 1700fps. Any body have any experience with this? "
I have shot several deer with the 45-70 using cast bullets from trapdoor levels to .458 Win Mag (510 gr cast GC at 2050 fps) out of trapdoors, Marlin M1895 and a Siameze Mauser converted to 45-70. First two deer I shot were with Lymans 457483, a 400 gr GC bullet, cast of WWs and velocity was right at 1700 fps out of the Mauser. One shot was all it took for both as I didn't see the second deer standing perfectly behing the one I shot. Range was maybe 75 yards with the bullet going through all four front quarters. Both deer died on the spot. Subsequently I have shot several other deer with the same bullet and a couple others including the Gould bullet.
The Gould bullet is a PB bullet and when cast of softer alloys that reliable expand I could not get any decent or "hunting" accuracy with it over 1500 fps in any of the rifles mentioned. Cast harder of WWs it would do ok upwards of 1700 fps but the one animal, a feral goat, I shot with it was flattened with the bullet shattering instead of expanding and all I found was chunks of the bullet in the off shoulder. Both shoulders were pretty much ruined. When cast of 1-20 alloy or magnum chilled shot (with 3-5% antimony and water quenched from the mould) the Gould bullets are a very deadly bullet on deer and accurate when velocity is held to 1450 fps or so. Some report driving them faster with accuracy but I never could get them to do it.
Actually a good RN or particularly a FP GC bullet cast of 1-20 or the water quenched shot will shoot quite accurately up through 1700 fps and give quite good expansion, even on deer.
Remember that 405 gr and 500 gr 1-16 arsenal 45-70 bullets at 1300 to 1400 fps were killing deer, elk, grizz and hostiles with little difficulty a long time before the advent of "modern jacketed expanding" bullets with out too much problem, they still will. It was really a 405 gr bullet out of a 45-70 M813/'79 trapdoor that "won the west", not a 200 gr .44 cal bullet out of a lever action.
Larry Gibson