barneyrw what kind of house do you live in? Mine is made of 2x4s here in Texas. That means the studs are 1 1/2 inches by 3 1/2 inches in size, so I can't get 4 inches of wood to hold on to, so I don't believe you can either.. Plus the Sheetrock will be where you get your purchase, real easy to get a pry bar between the safe and stud, you have only 1/2-5/8 of soft gypsum to crumble out of the way. Then you have a great space to work with. Your lag screw is a good idea, if it did not take up so much of the stud material, and weakened the stud. Are you absolutely sure you got it exactly in the middle? You don't have that much room on either side to work with, and since you can't see the stud, it's hard to judge. Also are you sure it did not come out the side? Studs warp and twist as they dry. (Trust me on this, I build homes for a living.)
Well you don't have a safe, because Canon does not make them, it's a RSC. Yeah don't listen to what the mfgs tell you, they probably lied to you when they sold you that "safe".
I don't own a bb gun, I took the racks out, that is how I got more guns inside. It does not bother me to have to move a few guns to get to the ones I need, at least most of them are in there. I don't believe in putting a gun you might need in an immediate emergency in a safe, takes too long to open and get it going.
Yours bolted to the floor will be loaded up and gone before they even get mine lose
Not a chance kiddo. How do I know this, because I understand how yours is installed, and you don't know jack about the other ways mine is secured other than it is bolted to the slab.