This should be a fun topic.[8D]

The current rage now is round pin guards and the theory that you should center your pin guard in your peep sight before aiming. I do not buy into the theory and believe it was dreamed up by someone who was making sights with round pin guards and had to make up SOME story so that people would buy them.

Unless you use a single pin that is perfectly centered in that round pin guard, I believe you should center your pin in the peep and completely forget about the pin guard. When you are aiming, your eye is going to naturally center the pin anyway because it's unnatural for it to do anything else.

Your eye likes concentric circles. Concentric circles practically force you to focus your concentration. Check it out...

http://www.michaelbach.de/ot/mot_enigma/index.html

Scopes with circle aim points are really popular with spot shooters for this very reason. Center the housing in the peep. The aiming circle is centered in the housing. The X ring is circled in the aiming circle. It makes it seem like you're shooting down a tunnel, so you can't possible miss.

This doesn't work with multiple-pin sights though, since only one - if any - of the pins can be centered in the guard. They will be non-concentric circles within a circle. Your eye doesn't do so well with non-concentric circles and will allow your concentration jump around. If you really try to force your eye to do what it doesn't want to do, it'll freak out. Like this...

http://www.michaelbach.de/ot/mot_ske/index.html

Your eye wants circles to be concentric, so it is going to naturally disregard the pin guard - since that is not one of your primary objects of attention - and will automatically center the pin in the peep. You probably won't even notice it, might even swear on a stack of Bibles that the pin guard is centered, but it is NOT centered when you finally release that arrow.

So, I say avoid the middleman. Disregard the pin guard and go straight to centering your pin in the peep.