In Team Fortress 2 when the Demoman uses the Charge ability his speed is increased but he is unable to turn quickly. You can increase your ability to control the turning by wearing 'Ali Baba's Wee Booties' or 'The Bootlegger'. Wearing either of those items will increase your turning control by 200%.
Players that are able to turn better than you are probably wearing 'Ali Baba's Wee Booties' or 'The Bootlegger'.
TF2 Server operators who want to try playing a Demoman with massive turning control and try using the '[TF2] Be the Mighty Samurai' plugin written by <ahem> me. Here's a link: https://forums.alliedmods.net/showthread.php?p=2740205