I use the same bullet for both my .223 and the .22-250, Hornady 52 gr. BTHP, and 3031 powder. My .22-250 is an older Rem. 700 BDL, my .223 is an even older Rem. 788. It took me some time fooling with different powders before I settled on 3031, tried Varget, and a couple others, came back to the ol' standby, 3031. My older .223 loves the 52 gr. BTHP, 5 rounds into one ragged .345 hole @ 100 yds. Your mentioning a different trigger, I installed a Timney trigger in the 788, best thing I ever did for a firearm, except cleaning rods and brushes.