i use the cx terminator hunters. 6075 which is roughly 11-12 grns per inch. bought a dozen and only had one that wasnt perfectly straight. they come in approx 6 gn diff per box. mine went from 361-367gn.. 3 being 361 then 9 being 366-367. when i fletched them, now they are all within 1gn and shoot extremely well. have some cx hunters 400 as well. i dont see a difference other then the weight. i just love shooting these arrows with my havotec. really quiet w/out any silencers.