I am not sure what I'm doing wrong, but every time I attempt to use my deltoids as a target, I end up with a lump under my skin and a bruise. Every time. Injecting into my quads, never an issue. I'm trying to get a better rotation of spots since I am doing 2x a week now, but I've been sticking with quads because of the bruising. Maybe 1/2" isn't enough?