i use my bi's as my secondary site (glutes first). i can't do my quads because it locks them up too bad. i have a bunch of 22g 1.5 inch pins from when i was using non-micronized suspension. i have been using them to shoot prop/fina in my bi's. haven't had any problem. i can get away with the long pin because i have bigger arms. i don't recommend it unless your arms are 20+ inches.