I don't know when I'll get a chance next, today was a range day. Mostly trying out some loads. Only going to note a few of those. All .45-70, all at 200 yards.
I've mentioned before- I think- that with modern cases you cannot get 70 grains of black into this case and have the bullet seated so the case covers all the lube grooves*, especially with a heavy bullet like this. I have gone up to 68 grains, and it takes a LOT of compression; 70 would probably cause the case to bulge a bit. There's a writer named Mike Venturino who's written a lot on .45-70, and has expressed the opinion that with most rifles you can get as good a performance with 65 as you can with more, with a lot less compression. So this was five rounds over 65.0 of 2f, using a .060" wad under the bullet
This one was the same bullet and wad over 24.0 grains of Accurate 5744, which is one Venturino really likes for this cartridge(so do a lot of other people)
I did try a few with the Lee 405-grain hollowbase over 26.0 A5744, didn't group as tight as last time. Which is quite possibly me, by that point I was getting to the 'concentration slipping' point. Ah well, I've got a few more for next time.
By the way: I can't remember if I mentioned this before(and I'm too lazy to check right now), there's a very good piece(in pdf form) on 'Introduction to Black Powder Cartridge Rifle Loading' by a guy named Chuck Raithel available online, and it's got a lot of good information in it. I'd post a link, but the one I had saved isn't working right, you should be able to search by that title and find it.
*A lot of guys loading specifically for long-range matches will seat the bullet as far out as it will go until it almost touches the rifling, and do not crimp; that lets them get as much powder in as possible for a little more velocity. It also means some of the lube grooves are exposed, and if you turn the cartridge over the bullet will fall out. Not shooting a those kind of distances, I want the case to cover the lube grooves, and use enough crimp to keep the bullet in place. That's with black, with most smokeless propellants you get better performance from a strong crimp as well.