i only have one gun boot so far there not bad but the liner isnt that great i know my 45/70 gets pretty jammed in there the boot its self fits pretty securely in the rack Like Morsno says get series IV I believe thats the only boot that will fit.And shop for the boot other than yamaha i got mine on sale 40.00 cheaper at Cabelas
I have the same gun boots as Traxnorth above. I run two all the time in hunting season and I am using the factory Yamaha mount. It works great no rattles and the boots sit in there solid. They are also easy to get out at the end of the day when you get back to the truck. I would definitely recommend if you carry a couple of rifles. The kolpin boots are pretty roomy, I have a BAR Shortrac with a Trijicon reflex rx30 mount on the top of hit which is pretty tall and it fits no problem.