Trapdoor Rifles

Hello to all from South Carolina.

I a 72 year smokeless powder reloader but now want to reload and shoot the 50-70 round through a couple of 1866 2nd Allin Conversion Trapdoor's. Both have been checked by gunsmiths who specialize in the TD. Can any of you offer suggestions on how to start this journey. I cannot find a local reloader to teach me. I've seen becomes listed, some recommended and some not. I thank all in advance for help that can be offered. I due have the Dies and reloading components except for the powder.

Thanks,
DocJoe

Doc,
Start off with Wolf's book, "Loading Cartridges for the original .45-70 Springfield Rifle and Carbine". This will get you started on the right track. I'm 71 and if you ever get to Charleston I'd be glad to meet you at the DNR range, go over black powder reloading and make some smoke with 45 and 50-70s. The bad news is that the powder rules in SC are awful, so nobody in the state sells black powder. You have to order it from someplace like Powder Inc. and pay the haz-mat fee. By far the best powder to get is Swiss 1 1/2 F. It is very close to the 1870s military powder, so close that you can get the original velocities with 65 gr. or so. If you use GOEX or Sheutzen, get 2F or 1F. Velocity will be down, but it will shoot well. 70 grains won't fit in a modern solid head 50-70 case, and you will need a powder compression die to get 65 grains in there with the Springfield bullet. Look on Buffalo Arms website for compression dies. They are essentially neck sizing dies, but are longer.

One thing about Springfield 50-70s, the chambers are very long. They shoot better if you trim 50-90 cases to 1.85" length (and then 70 grains will fit in the case).

Thanks for the feedback. I know about SC's rules on BP. I'll do some reading and message you.

Great information Tony!! Believe I have some 50-90 cases?? If I do I'm going to give that case length a try along with swiss 1 1/2 f that I ordered by mistake some time ago.

I have been reloading , casting and shooting 45 and 50 70 for a good while. I lucked into TRAIL BoOSS smokeless equivalent and walked away from the holy black stuff. I cast 450 grain bullets for my 50's and load the trail boss powder to fill it to base of seated bullet. It's an excellent load , works great in my traps , and sharps. I have even loaded it in 11mm werndl with excellent results as well as 455 webley pistol using original profile webley cast bullets . Trail boss is hard to get with all the Ukraine war thing raging on as Russia & china were the biggest suppliers for raw nitrocellulose products. Those supply avenues are cut off whilst they make munitions to kill each other. Another great powder is Vitvhouri N32C tin star for BP volume load equivalents...but it too is unobtanium these days.