I agree with mw about the vest riding up or slipping back when there is weight in the game bag. I have the basic model of strap vest and it has a leather belt in front which I slip under a loop from my pants and this takes care of the slipping. I also added a piece of suspender elastic strap with a clip on each end to keep the straps closer together across the chest

'Often mistaken, never in doubt'

'Ignorance more frequently begets confidence than does knowledge' Darwin