I went through the same thing, i ended up switching from the Gold Tip 55/75 w/ 125 grain heads to Carbon Express Terminator Hunters 60-75 with 100 grain tips. They are grouping very well for me.

at 26" arrows w/ 100 grain tip mine work out to 456 grains and FOC of 8%. Yours would be 27 " so add 12 grains, arrow weight would be 468 grains, FOC would change slightly also.