In tring to figure out what weight broad head to shoot I was just wondering what the difference between 75 grain and 100 grain is. I u know 25 grain but in terms of speed, are they much slower? I just shot through a crono graph with the 75 gr and I was 260 ft/sec. I cant get back down to shoot 100s till the end of next week. Any predictions/estimations of how much slower the 100s will be? Also in terms of trajectory, I will the 100s drop quicker?

I am shooting 64#
28.5" GT XTHunters

Any advice would be helpful.