i am shooting arrows by a small company named forge. they seem to be very strong arrows, i have only shot them for a short while, have done little stump shooting with them but i have shot several trees straight on and glancing shots and i haven't broken a shaft yet. and the guy i lease from has shot them for awhile and he is a dealer, he said they are the strongest arrows he has shot and that they are made with kevlar, they do not advertise the kevlar part on the website.
yes they are extremely light gpi, i pull 29 in and have several inches hanging over, i suspect that i could go down from 7.8 to 6.9 gpi arrows and cut them off and they would be plenty stiff then i could add the extra 31 grains to the front and get a 35-40% foc arrow. but they are pricey arrows so i got the ones i KNEW would work.