Shothgunner,
I load light cast bullets for the 45-70, enough that I use my Hornady Progressive press, and I (we) cast for 3 other shooters, so we tinker to no end.
We shoot Encore's. H&R Buff Classic, Marlin 1895 and Sharps Repros and my Browning BPCR. For the levers we cast RCBS 300 GC, SAECO 350 GC and Lyman 405 PB even a SAECO 475 GC FP. I have 9 moulds for 45-70 300 to 550 gr, so the combinations are unlimited. The light weight bullets are nearly all for plinking steel at moderate range, with accuracy and reduced recoil the goal. The shooter with the Encore prefers the 300 and 350, same as I do in my 1895 CB. He uses Unique, following the data from the Lyman cast bullet manual. The RCBS mould casts the smallest, but for the Encore we've found that if we cast the softest bullet we can blending WW2%Tin with lead that will still keep the gas check fimly in place we have the best accuracy and leading has been non existent using good lube and sized right at groove diameter. The Encore can really thump your cheek if you stoke it up but it is splendidly accurate with the Unique loads. But using Unique you must take every precaution against double charge. Don't get me wrong, we have tried all the Rhino Stopper loads, maybe it's our casting and loading techniques and powder choices , but for the fun to shoot loads, we've moved to the softer alloys. Folks at Hodgdon, LBT and Lyman have been invaluabe resources.