ORIGINAL: davepjr71
The GT 7595's would be underspined atyour arrow length and a 125 gr tip @ 70 lbs and a 29" arrow.
You'd probably need a spine of .320 or stiffer from any manufacturer for an arrow that long and definitely with a 125 gr tip. You probably should the shorten the arrow as recommended by Joe PA if pssible with your bow.
My buddy has a 29" draw and uses a 28" arrow and 125 gr tip with the 7595 series and is slightly overpined for his Matthews. That same arrow for me is underspined for my Allegiance.
I think there is another factor here to be considered like what is referred to above. Dave mentions itbeing the differencein the camsbetween the two manufacturers, Mathews and Bowtech or any other maker, one is a bit less hard whereoneis a bit more in cam turn over. I know several bow techs that believe this and your saying the same arrow will performdifferentwhen shot out these two bows. Especially when your close in spine changes for the charts made for an arrows use. Just my .02