I have come to the conclusion after all these years that you want the smallest pin possible. I shoot a .019 fiber on both my hunting bows and my tournament bow. I have found years ago when the fiber optics first came out, the bigger ones in low light will be toobright and cover the animal in low light situations or make a glare. Just my opinion, also if you shoot a peep you will want the biggest available for hunting (I drill mine out even more) and my tournament bow has the small peep on it and in the situation where you shoot the same bow for both hunting and competition I would go with the bigger peep rather than a little one, this has cost me a deer before late one evening, nice 8pt. too. Like I said before these are just my experiences hope they might have helped you out.