Firing range Easter egg has been found!

basically the dummy’s move and kick you if you get close how you do this is you drop all your stuff as you enter the the training mode so the p2020 and the ammo 

make sure ur pathfinder I forgot then after you drop everything grab a blue shield and stabiliser then 4 packs Energy ammo then you run to the fifth cave after that you grapple up To the top then crouch and look down then change your legend then bingo you run down then there you go the dummy’s are moving