just a tip or two,
(1) use gas check, cast bullet designs, they consistently provide less bore fouling
(2) use 215 fed primers as they seem to be the most consistent in my testing
(3) size the bullets you cast at .459, sized any smaller and accuracy seems to suffer
(4) if you graph out bullet weight vs velocity , and retained energy at 100 and 200 yards,

you get a curve indicating the 350 grain -420 grain weight is about ideal, in the 45/70 and 450 marlin rifles

all cartridges should be loaded to near max length the magazine can handle for best functional durability/consistency
as the loaded cartridge length must be rather consistent, heavier projectiles take up more of the available powder capacity, one reason projectiles over about 420 grains are not ideal.
http://gaschecks.castpics.net/index.php?main_page=product_info&cPath=3&products_ id=17


heres a few molds I find work well.
http://www.neihandtools.com/catalog/index.html


the 355 seems to shoot well with most powders


the pointed 405 can be used in the browning BLR box magazine but its marginally less accurate than the 355 grain in my experience, your rifle might be different
BTW I cast my bullets from 95% WW alloy and 5% pure tin, sized and lubed to .459 diam


https://www.midwayusa.com/product/63...nose-gas-check

heres jacketed bullets well documented to work well,in a 450 marlin

https://www.hornady.com/bullets/rifl...nterlock-rn#!/

https://www.midwayusa.com/product/16...ain-soft-point

https://www.speer-ammo.com/bullets/r...-350-fn-bullet

https://www.speer-ammo.com/bullets/r...-400-fn-bullet

IMR 3031 and WW748 , and RL7 powders all work rather well.

https://www.hornady.com/bullets/rifl...nterlock-rn#!/