I think you would be better off trying to get heavier shafts than sitting a 300 grain arrow on a carbon shaft. I shoot wood arrows and shoot in the ground and anything and all I hear from compound shooters is "check your carbons for cracks" and they shoot into bags. I am not sure I would be very comfortable forcing a carbon arrow to flex that much to start a 300 grain arrowhead moving.
I know it will sound kind of contrary to you, but if you made shafts like a traditional guy, I have seen 650 grain arrows made from Ash with 125g tips and its very tough. Increase the weight of that point and you increase the thickness of the shaft and could be over 700 grains easily. Ash is probably the toughest and heaviest arrowwood on the market.
I shoot hand made shoots from hardwood with 125g heads and easily hit 550g arrow eight with a 42# spine for my selfbow. If I shot traditional and could up my spine to 60# for a 55# bow It would probably make 600g easily. Add a 150 - 175 grain arrow and I would probably hit 650
Just food for thought.
Last edited by archeryrob; 08-14-2017 at 04:21 AM.