I reloaded about 60 rounds of .45-70 with above said powder behind a 405 hardcast bullet. I found the data in a Hodgdon reloading magazine a few years ago. The listing was specifically for Trapdoor loadings. I don't recall the data in the magazine, but I started on the MINIMUM load and went no higher. I tried it out and...it felt like a .30-06. A LOT hotter than factory loads. In fact, last time I shot it, I put about 6 rounds through it in offhand shooting position. Hard to keep it from knocking you back a little. With all the talk about it being such a "weak" action, I was truly surprised. The gun doesn't seem to mind it either. There are hotter loads for Lever action and Rolling Block in the same magazine...but I really don't see how you'd need to go any higher.
FWIW, I to have the Pedersoli Carbine. I've only shot black powder out of mine with a 405 g bullet. I use 55 grains of black powder, instead of 70. This is what was done back in the day, and I've heard referred to as the carbine load. It will still knock down a horse on the business (a guess on my part, NOT from experience).
I did have an H&R Carbine that I shot some full trapdoor loads in. It was too much for me to shoot comfortably. I was using 30 to 32 grains of IMR 4198. Before I swapped over to black powder loads, I was down to around 25 grains for the IMR 4198 powder....it was a bit light. ;D
Having said all this, though not everyone shoots less powder in the 45-70 carbine than in the rifle, so folks do, and the 19th century Military did as well.
My Good Doug -
Big Bullet, big recoil. your example comparing to a 30-06:
30-06 150 gr bullet muzzle velocity of 2910 fps recoil energy of 17.6 ft/lbs
45-70 405 gr bullet muzzle velocity of 1330 fps recoil energy of 18.7 ft/lbs
here is some mfctr loading data for the trapdoor - note these are "old" pressure data in CUP rather than PSI:
Bullet Powder StartGrs ft/s Pressure MaxGrs ft/s Pressure ---------------------------------------------------------------------------------------------------------------------------------
405 GR LFP IMR IMR 4895 45.6 1496 18,900 CUP 48.5 1598 23,000 CUP
405 GR LFP Hodgdn H4895 40.0 1424 14,900 CUP 48.0 1645 18,900 CUP
405 GR LFP IMR IMR 8208 XBR 47.9 1637 21,800 CUP 51.0 1727 23,600 CUP
as one fellow put it:
"The max 8208 trapdoor load with a 405 LRN bullet is listed at 1727 fps and 23,600 CUP, so that's a fairly low pressure load. From experience I can tell you that pushing a 405 grain bullet at that velocity is going to recoil. That rifle might kill on one end and wound on the other. "
so ...... yup it's gonna kick.
yhs
prof marvel