I used NAP 100gr thunderheads for years along with 400gr Beman arrows. I switched to 100gr Schwackers about 4 years ago and Easton 400gr arrows with Blazer Vanes. I have really liked the Eastons a lot better than the Bemans. I have to buy new arrows and broadheads this year. Im not sure I like the schwackers impact. I do however like the cut diameter although one didn't expand correctly two years ago and I had very little blood. This never happened with the fixed heads.
I shoot 66pd and 310fps.
What broadheads do you prefer and why?
What arrows and fletching do you prefer and why?

100 different folks could reply to this and you'd have 100 different answers/combos! Whenever I'm thinking about switching stuff up, I always watch some of the head to head tests that give me actual data, and then, of course, shoot it to make sure I'm comfortable with it.

I have used both beman and eastons and both are great I didn't see much difference between them. I do like the blazer vanes. I use a nap shockwave and love them,never had problem with them opening and it has a big triangle tip for going through bone. I have shot some deer in front shoulders and and have had the arrow go through both shoulders.

If you're pulling 66# you'll need a 340 spine arrow. As for broadheads, those 2" cut mechanicals are nice, but they will never penetrate as well as a fixed head.

What the heck kind of bow are you getting 310 fps with 66#s and 400g arrows?

I believe he's talking about a 400 spine

I believe Easton and Beman are made by the same company just marketed under different names. Like Shaw said you'll need a 340 spine. As for broadheads that arrow at that speed should push anything you choose. Mechanical heads typically don't penetrate as well because they expend some of their energy opening the blade. Cut on contact don't do well with bones. I prefer a fixed blade with the trocar design tip such as wasp boss or muzzy. The trocar design tips do really well on bone after all it was designed by the trojans for piercing armor.

I'm shooting gold tip hunters and rage hypodermic 125's. Out of my set up (halon 6 -70lb - 30 inch draw. They are rough on them and get pass throughs

Easton FMJ Deep Six with rage hypo 100's has been a great combo for me going on 4 or 5 seasons now.

I'd up to a 125 gr head. I tried a few this year and I'm sticking with the thunderhead. I've shot several bulls with them and have had zero damage to the heads.