I am a relative newcomer to archery and only shoot a 55lb longbow but after watching the same bloke on tv (I think?. He was demonstrating distance shooting and also had an exagerated jump on release.) shooting with the exagerated stance I tried it. It does seem to work. It feels more confortable and natural and I would even say it adds to speed of release and accuracy, as with practice the actions of lifting, aiming, drawing and shooting seem to blend into one flowing movement. Does this sound plausable or am I talking out the back of my neck?
You feel a right prat doing it though!
