hey congrats on your purchase.i collect 44 carbines,they are a nice little rifle.one of the tricks is to use no more oil than necessary.more oil will only hold more contaminants,dirt,powder residue etc,and also gets thick when cold.i have the best luck with rem oil,it is very thin with a teflon base,either in a tube or aerosol.i apply with a lambswhool applicater trying not to leave to much extra.make sure all the grooves in the receiver are clean and the gas piston and housing as well.they sometimes are overlooked.
as for ammo i handload with a 240 grn bullet.the 240 makes a nice combination for that rifle,i never had much luck with anything heavier,never had trouble with those loads operating the action.over the years i have killed a pile of deer with the 44,a couple out to at least 125 yds.
keep it clean,it'llkeepyou happy,good luck,adker