I think if your lean, You can hit Bi, Lat, Chest, Tri with 5/8". I'm 10% and less at times and thats what I use. 25 GA is nice as well. If your fatter that 10% or 11% use a longer pin.
ya no now that i think about it this is kinda of a stupid question because i have always used spot shots with a 1 inch pin just did not sink it all the way so i guess i was probley only going 5/8 or so in anyways thanks tho for the replys tho