You didn't say if your arrows were grouping ok w/ field points. Knowing that would help. There are alot of different opinions on what is best. I have 3 xbows and shoot the same setup outta all three, GT LII's w/ 100 gr Slick Tricks, 1 1/8" diameter. You might want to buy/build an arrow spinner to check your b-head alignment. You can make one by epoxying 4 marbles to a piece of 2x4. Some guys have real good results w/ mechanicals. The field point groups are the starting point, be sure to check them at 30 yds, which is where real problems start to show up. Fwiw, the arrows I'm using have brass inserts and weigh at 431 gr, w/ a FOC of about 20%. I "adjusted" them down to 15% FOC and could see no difference in group size. 10 pt sells basically the same arrow w/ choice of nocks, [flat or moon] at Cabelas or you can order these from Danny Miller at 740 483-2312 at $5.75 ea. Don's advice about centering the string was right on, make sure of that 1st. Good luck!