I agree with Arthur in that your arrows are way underspined for the weight and length, with a 125 gr broadhead. Probablt with 115's, too, but apparently you're getting away with them.

Can't say why people don't think about it, but with an underspine issue the cheapest and easiest way to get them to fly is just drop some draw weight off the bow. Alas, most people are averse to this as they think they need tons of KE to get the job done. Seems that one of the best tuning gadgets put on a bow are the last to be considered to get good arrow flight. They are called limb bolts. Bows are adjustable for a reason.