I shoot mostly Cowboy Action shooting loads in several 44 Magnum Original Size VAQUEROS/BISLEY VAQUEROS with 5.5 inch barrels...also a 7.5 inch gun...long time Richard Boone fan...Paladin in HAVE GUN, WILL TRAVEL tv show 'way back when. BUT I also use the same loads in a MARLIN Cowboy rifle.
I like various bullet weights. Full wadcutters in 200, 230 and 250 grain; semi wadcutters in 250 grain; round nose flat point...feed better in the rifles....from 240 to 275. Almost all of them are plain base designs. Gas checks are an un-necessary expense for mid range/low end loads. Get the HODGDON Cowboy Action pamphlet for the lighter loads and fine tune a bit. Powders I like are TITEGROUP, HP38, RED DOT/PROMO, UNIQUE and HERCO...all of them in the 5.0-to-7.0 range for starting loads, depending on your recoil sensitivity. ALSO they deliver over 1000 loads per pound of powder.
I size anywhere from .430 to .432 in my STAR lubricator sizer, depending on as cast bullet size, since I am loading for a bunch of 44 pistols and rifles for myself, step kids and grand kids. The .432 seems to work well in most of them, but an individual gun may not like them. A set of LEE push through dies to reduce sizes would be a good investment before buying a sizing die. AND LEE LIQUID ALOX is a good system to get you started with lubricating and sizing your first home cast bullets. A little time consuming and messy, but a CHEAP way to get started and it does produce good results. Go over to castboolits web site and do some reading. The lasc.us site has some great articles by Glenn Fryxell and his book, FROM INGOT TO TARGET, will educate you to the level of guys who learned everything the hard way in years past.
REMEMBER: Just because the casing says MAGNUM doesn't mean you have to load it hot.