Go here for lots of good info on lever action rifles plus suggestions for lead bullet loads in marlin micro-groove barrels.
You kow whats funny? I sold my marlin 1894 in 44 mag with a MG barrel so I could get a newer ballard rifled 44 mag and I have never shot a single lead bullet through it. And the real kicker is that my old MG barreled gun was more accurate than the new gun. Don't sell a micro-groove barrel short till you give it a fair chance.