The Longbow was used significantly through the sixteenth century, and still in mass numbers. I would say after the battle of Pinkie in 1547 was when the Longbow was finally being edged out for the gun and that was just due to the fact that it was easier to use and to train men with rather than any advantage in fire power.

I still believe that the artillery used by the French was vital in the reudction of the fortresses in Normandy and Gascony but if we look at the battles near the close of the HYW their was alot more than to it than cannon winning the day. Formingy saw the English outnumbered with inexperience troops from England, attacked on two fronts and adopted an L shaped formation and after an bombardment by two culverins were forced on the attack. Castillon saw the cannon and small arms protected by ditch and pallisade as the French still feared the Longbow in open field.