When I load my camper, I put a 5 foot 4x6 and a 5 foot 4x4 post on top of the 4x6 against the front of the bed laying down with the 4x6 laying on the 4 inch side. This keeps the camper snug and stable to the front of the bed and avoids damage to the truck and camper. When I unload I put the 4X6 about 2.5 feet from rear underneath on 2 Camco screw jacks ant then the same with the 4x4 in the front. I store it for the winter the same way. My dry camper weight is around 4500 pounds.
The extra support takes some of the stress off of the jacks and jack mounts. This is my second truck camper with swing out dually brackets.
The last one I had came with rubber bumpers for against the bed, the new one did not so I bought 3 inch bumpers from Tork-lift, but felt any type of mounting hardware would not be robust enough to mount them without damaging the camper. Our first truck camper was an Empire built in 1973 and used a dicey tripod had crank jack system that was unstable as can be.
