Hey chop - I just purchased the ATV Carry all (API Outdoors) for my Polaris. They make a Polaris model and one for all others. It fits on the back and is a combo tree stand (climber) and gun rack. It is very solid and what I like about it is that is frees up your front and rear racks for other things - deer maybe? I got mine from C & S Sales over the web. $50 bucks -free shipping. If you just want a gun holder fin grips work well - Cabelas or Bass Pro/Redhead, etc...

http://www.candssales.com/