I have a 30-30 Marlin ,Migrogroove bore,but without the hammer blocking safety.
It accepts 310 NEI bullets designed by CE Harris for the 7.62 x39 .and shoots ,1-1/2 moa groops at 100 metrs,with an old 3-9 tasco scope.at 1250 fps.
I use the scope on leverguns just for developing accurate loads,the scope ruins the wonderful handiness of leverguns ( SCHIOPPETTO MANESCO in Italian)
I use win Large rifle or Rem LR Magnum primers,using a double base shotgun powder(made locally,it's name Tecna),similar to your unique.
I size the bullets so they enter the neck of a shot case,I mean a not yet sized case.
Measuring the throat,expecially in the 30-30,that most of the times has practically no throat ,is too difficult to me.
Hunting loads,over 1700 fps,will probably need harder bullet than straight air cooled wheel weights.
I use the easy to perform trick of casting high temp bullets (frosted surface)and dropping them directly in a pail of water.
Let them age a couple of weeks,and they are perfect,they have a hard skin and an expanding ,not shattering in fragments, core.