RE: Bow Square Question
It depends on the rest you are using, the type of release, the way your nocking system is set up, etc...
I set up single cams about 1/8th to 3/16ths nock high. This is a good starting point. With your nocking system, single nock below your arrows nock and inside a loop, the pulling force is slightly below the arrows nock and in my experiance this causes your arrows nock to need to be even a little bit higher than normal.
If you loose that brass nock you got in there, cause it is doing absolutely nothing but robbing you of speed, I bet you that your arrows nock will sit right where the brass nock was and it will shoot even better.
Why would you still want a brass nock if you are shooting with a loop?
Oh yeah, you should be measuring to where the center of the arrow is not to the top or bottom side of the arrow. So if the bottom of the square is touching the prongs then you are measuring it wrong and it should be moved up a bit. The center of the shaft sits above the prongs.