I bought some 5/8" 25 gage pins just for delts. But even when I sink it as deep as possible (I leave a star impression in the skin from the needle holder) I have had oil leak back out the injection hole when I withdraw the needle. 1" pins cause substantial pain for about an hour post injection compared to the 5/8" but what good is less pain if I'm losing product?

I can use the 5/8 pins in my quads because I can use both hands and pull the skin over prior to inserting the needle, and release it when done, and skin covers the hole. I think its called the Z method.

Also first few times I hit any virgin muscle resulted in wicked pip. After 4 or 5 times the pip drops to almost nothing.

Insulin pins can work in shoulders. Ive got those but the 25 x 5/8 is a lil easier. Warm your bottle prior to kill some of the pip. Need 25 Ga for quads IMO if quads aren't fatty. Rotate sites every time