1873/1884 Trapdoor

I recently traded a FG CMP HRA M1 for a 1873/1884 Trapdoor. I should have researched before I did it, but whats done is done. Now, I have a rifle I know nothing about(except what I've read here) and many questions. First, I want to shoot this but, see many say, "Use smokeless powder". I believe it shot black powder originally ,so I'd like to shoot blackpowder. I do not have time to reload so someone said go to Buffalo Arms.com. Do any of you know them? Next, 45/70, bullet grain? 405? 415? 500? I would really appreciate any knowledgeable opinions. Thanks in advance.

You have acquired the version that I would find most desirable - with the 1879 buckhorn backsight. This is a great improvement over the 1873 stepped ladder sight, with a continuous ramp and windage adjustment with scale markings. Many will say that the 1885 Buffington sight is even better, but that is often not permitted in service rifle competitions over here.

Of course it is a blackpowder rifle, and should be used accordingly. If you look in the Lyman Reloading Handbook you will find appropriate warnings included with the 45-70 reloading data for smokeless powder.

The original bullet weight was 500 gns. 405gn bullets were introduced for the cavalry carbines, but are definitely too light in the wind at long ranges. All BP shooters of my acquaintance use bullets of 500 gns or more, as the longer bullets are quite simply more accurate.

Used properly (with BP and a 500-520gn bullet) the Trapdoor is one of the most accurate BPCRs, and a regular match winner.

Buffalo Arms seems to be the major provider of obsolete BP ammo in the USA. I have no experience of their products, but I suspect that if you get to like shooting your Trapdoor, you will soon be taking a serious interest in reloading, if only to relieve the strain on your purse.