A while back I wandered into a 500 count box of Hunters supply 240gr flat nose hard cast that do real well out of my Ruger SBH and my H&R Handi , Yet i still dabble in the heavier bullets for both those weapons .. Have had good luck with the 300 gr Hornady XTP , Groups are good in both , havent taken game with it in that caliber yet. tried Win. 296 and Alliant Blue Dot and I think I tried some loads using Bullseye as well.. I decided to stick with the W296.
The Same 300gr XTP I use it in my 444S ( 1973 manufacture date ) Marlin with the 22" barrel . I get 1" +/- groups at 100 yards , This load took a mature doe at a walked off 90 +/- yards with only about 7-8" of head and neck exposed behind a fallen tree , Well the accuracy held and a 300gr XTP in the neck 2" bellow the jaw left no doubt as to the out come.
Couldnt be happier with that loading in my Marlin, It was used in combination with R-P Brass / CCI BR2 LRP / And Alliant Reloder 7.
More recently I had my long awaited order from Bear Tooth Bullets come in, A 330 gr LFNGC with a double crimp groove , In R-P brass with the BR2 primers and Reloder 7 right out of the gate are showing great accuracy from the off hand 75 yard shooting i had a chance to do a couple weekends ago. Havnet had the BTB 330gr slugs long enough to try them out of the 44's yet , but then again i didnt purchase those bullets for them either but it has crossed my mind
Hope this helps you out a little