Agree with Mr. Snakes...maybe use on the deltoids if you insist on using that size? IMO 23g 1" is the best all around winner for AAS IM injections. As far as your 5/8" goes, how much SQ fat do you have? Also, there seem to be some guys who just have "thicker" fascia tissue...they never get that paper thin look and you know they must be using darts that came with the old redi-ject sus. If you are not getting deep enough into the muscle tissue you may run into a little health hazzard a week later...not to mention you may have wasted a shot a of a good drug.......heaven forbid!