I used a 50 cal can for my cams. I put screen door pull handles on the back of the can, and use a ratchet strap to attach it to a tree. By next fall, I am going to come up with some type of chain attachment to be able to lock it to a tree. So far I have not lost a cam, but I don't want to press my luck. This also holds it out from the tree just far enough that I can get the lid open without any problems.
After re-reading your message, I think that you are asking about mounting the stuff in the ammo can. Maybe I didn't help you after all with this post.