I draw with an 18g and shoot with a 27g 5/8 inch pin... I am usually around 10% BF so I dont need to get too deep. I have been doing this for YEARS.... Everything from NPP, Tren, Test Cyp, Prop, Sust have flowed through it. No heating or anything.. It takes about 30-60 sec to hit under 2.5cc's. I dont mind the 30 second injects as opposed to a larger pin..