I have made them like that before, cant say there was any differance from the round to fire, did find they seem to sit in the pouch better, I made mine by drilling a load of 10mm x 10mm holes in a chunk of aliminuin and just top them up, jeff
I use oval sinkers because I can't get roundball. They have a hole from tip to tip. They're better than split rounds, but though they look bullet shaped, they hit any way they please. End on, side on, whatever. It's random.
Splitshots IMHO are too irregular causing it to go off course. I have mostly used round lead balls of different cal. they do fly straighter but i dont think that round balls penetrate or do as much damage as torpedo shaped/ other irregular shaped sinkers.