I've been messing around with shooting black powder 45-70 cartridges out of my browning 1886.
Using duplex loads I was able to make some accurate loads that would put all the shots in a 4 inch group at 100 meters  ( good enough for hunting ).

I've stopped duplexing as I want to make cartridges with just black powder , I've tried graphs , goex and old eynsford. I was able to get the Old eynesford 3f ( 55gr ) and my cast 405gr Saeco bullet to print a ragged hole at 50 meters but it opens up to around 5-6 at 100 meters. I'm using over powder wads from cabellas and home made black powder lube with natural bees wax.

Does anyone have a load that works for them ? I'm getting a little frustrated trying to get this rifle and black powder working together.

Have you slugged your bore to verify dimensions and sized your boolits accordingly? How about the throat?

Old Eynsford is supposed to be good. I think Swiss BP is still the almighty king, though.

Another thing that is supposed to improve consistency is compressing the charge and then just soft seating the bullet in the mouth of the case.

Yeah , I need a 456 bullet . My bullets bearing surface is 456 and I have a 457 driving band. I can't soft seat because i am using a lever action and need a little crimp to keep the bullets in place. I just loaded up some more cartridges with 60gr by volume ( measured on the scale at 61.7gr ) of old eynsford 3f. I'll keep walking up the powder charge by 5gr until I get to 70gr by volume. I might try seating my bullets a little longer to make contact with the lands if this doesn't work. Someone on another board also said that they couldn't get their browning to shoot lighter bullets so I might order a 475gr Parker hale maxi bullet mold if I can't get an accurate load with the Saeco bullet, someone on one of the lever gun websights said their friend uses those to great effect.

I'll keep this updated as I continue and try and work out a load.

Attached File

Accuracy for multiple shots only comes with fouling control.  I shoot sharps rifles with black and blow tube between shots.  Others swap after every shot.  You didn't mention which bullet you are using or what your lube is made up of specifically.  It will take a lot of lube to keep the fouling soft for multiple shots without blowing or swabbing.  You may get better results with a grease cookie under the bullet.

I've been thinking about that , I think I'll give it a try , My progress has been slowed a bit , just had a new baby so I won't be able to play with my loads much for a few months. I'll definitely try the grease cookie next time I get to go out though!

I fire the Lyman Postell bullet in 45-90 / 45-110 and it will do MOA with iron sights if I do my part.
I fire a compressed load of Goex 2FF , veggie .030" wad over powder and bullet seated in contact.
Lubed with beeswax / olive oil mix.

You need a powder compression die for better load density / accuracy.