Reloading for an original 45-70 trapdoor

[Major Tom]

I have loaded 45-70 with black powder with no issues. However, I want to load now with either Pyrodex or Triple 7 with a 500 gran bullet. Does anyone have loads they use and can share?
Thank you

[JB White]

Pyrodex you can use volume to volume ( not grain for grain) to your BP loads. Word to the wise:
Clean Pyrodex immediately. At least before sacking out for the night. On a humid day it will rust over ugly and you may need to soak to get the gun open let alone apart.
Haven't worked with Trip,e Seven yet.

[Sunray]

Only ever loaded for a TD Carbine, years ago. Used a cast 405 grain bullet with BP. In those days there was no internet to tell me that the load for a Carbine wasn't with 70 grains of BP. Or that BP is loaded by volume. A TD Carbine with 70 grains of BP hurts to shoot.
Anyway, the Lyman BP handbook and Reloading Guide has suitable loads for a TD using Pyrodex. Dunno about Triple 7. Probably data on Hodgdon's site.

[jon_norstog]

Only ever loaded for a TD Carbine, years ago. Used a cast 405 grain bullet with BP. In those days there was no internet to tell me that the load for a Carbine wasn't with 70 grains of BP. Or that BP is loaded by volume. A TD Carbine with 70 grains of BP hurts to shoot.....

That's why the carbine load was 55 grains.

jn

[JimF]

That's why the carbine load was 55 grains.

jn

As was the “cadet” rifle load.

[Major Tom]

I have ruled out Pyrodex and Triple 7 for reloading my original trapdoor. As for other smokeless powders, how do Alliant 2400, Trail Boss, IMR 4595 and Accurate 5744 stand? I assume using 2400 that a starting load 22.0 is OK? Accurate 5744 starting at 23.4 to max. 26.0 is OK? I will be loading the 500 grain soft lead bullet. As an aside, I got some once fired 45-70 brass. Most of it is Starline with a few Hornady. The Starline measures 2.10 inches and the Hornady 2.04. Why the difference?

[jon_norstog]

.... As an aside, I got some once fired 45-70 brass. Most of it is Starline with a few Hornady. The Starline measures 2.10 inches and the Hornady 2.04. Why the difference?

Starline makes a longer case and cuts it down. They make 45-90 and I think up to a 3" case, say 45-120. The 45-70 standard case length is 2.1". The Hornady brass may be a little short.

jn

[Sunray]

"...carbine load was 55 grains..." Yep. Found that out years after I traded the thing. Had no books and there was no internet to tell me that then.
There are smokeless loads for a TD on Hodgdon's site. Only up to 485 grains though.

[Major Tom]

I settled on a powder Alliant 2400 @ 22.0 grains under the 500 graind soft lead bullet.
Thank to all who responded!

[JB White]

I've used 2400 behind a 405 in a Handi Rifle but not in the 1884. Always kept those BP or substitute loadings.
Aside from the chambering there is very little to compare between the two. The H&R did OK with the BP loadings but prefers the smokeless.
Let us know how the smokeless/equivalent loads perform in yours? For the sake of curiosity, if you don't mind?

I let the trapdoor go a few years ago. Got more for it than I could have for the M1917 I traded for. But I still have the Handi as it's a bookend so to speak. 22 rimfire on one side and 45-70 on the other. Everything in between is a filler and anything beyond is 'something extra'. :-)