i have a buckmaster g2 and the paper work that came with it say the center shot has to be 7/8" but when i move it there the arrow fishtails and bad paper tears but when i move it to 11/16" it is perfect should i be worried or is this fine?

You will be fine the 7/8" is a starting piont for that particuler bow .
Where your center shot setting that you have at this point is derived from your form,and your shooting style.
Not everyone can use the recomended center for this reason.
All it is,is a starting point .it is the center of riser in relationship to the string.
The center shot for my Buckmaster 2000 is 13/16" and my actual setup for centershot is 7/8" for me.
Have fun and Keep practicing..

Could be your center shot is right but the nocking point may not be or it could be that you have a weak spined arrow or you could be getting fletch contact.