Back in our praire dog hunting days I loaded for 5 different 223s. 3 of them were Savage with 9" twist. 2 rem with 12" twist. I now have 14 twist on one of mine.
I found its pretty difficult to find a bad load in 223 as long as suitable bullets are used.
Since I bulk loaded on a single stage press I soon quit the extruded powders. Powders such as H335, BLC2, AA 2200, Ramshot exterminator etc all worked well and could push 50/55 gr to 3000 or above very easily and safely.
My most favorite bullet is Sierra's 55 BTSP. This is one of their game king line and nearly always exits with a nickel sized hole. The exit hole out of the back of a deers head looks just like the one out of a coyotes rib cage. I've killed a truck load of coyotes with this bullet. Alas it will not stabilize in the 14 twist I generally use so I shoot the 50 gr V max. It too is deadly on coyotes but rarely exits even on broadside shots.
Roughly 25 gr of any suitable powder behind any suitable bullet (50/55 gr)will throw 3/4-1" groups from a bolt gun so often as to become boring. This is one of those inherently accurate cartridges that it's hard to go wrong on.