Those who are shooting 300 fps. are no doubt shooting a release with an overdraw.
Overdraws? Are you serious. The only people that use those are just because that's what they've been shooting since the 90s and don't know any better.
I shoot 314fps w/ a 29"
carbon arrow... they just came out w/ them... ohh.. about 15yrs ago [8D]
But yes I do use a release aid. But the bow is 38" axle to axle and could in theory be shot w/ fingers... but the valley is very short and would be very hard on the fingers.