I've used 5/8" and 1" delts/chest, 5/8" seems fine IMO. Quad shots never worked for me, gave up on them long ago, they work great for many just not me. Only doing one shot a week I'm not concerned with trying to find tons of spots to shoot, since I have 8 that work well enough. Triceps I did several times but almost always found veins, nerve network is seemingly dense too.