Am I the only one who doesn't mind using 21g 1-1/2" for all my injects? It's fast to draw, fast to shoot, and I don't mind it a bit (even for things like bi/tri site injects).
But hey - if tren WILL go through a slin pin (and if BBF says it will, I'll take his word for it), maybe I'll give it a shot someday...
-M