Well it depends on the inline. Then decide if you want slip fit or pressure fit conicals. Some easy to make and good for short range (100 yards and under) are the LEE REAL conicals. In the .54 they come in a 300 and 380 grain. The longer work better in the fast twist. The 300 work will in the 1-48 twist.
Another good mold is a Lyman Maxi Ball. They shoot real well and are easy to load. I have a couple custom molds that work real good. I make a 450 grain slip fit that shoots real well.