Be careful about that walmart safe from sentry. I have a sentry and like it a lot. I got mine at a gun store, they sold them for 399 plus tax, I had them help load it and I was off. Mine has 5 locking bolts.
The ones I saw at walmart only had 3 locking lugs, but were still 400 or so plus tax. I would see if you can find one with more lugs for the same price, maybe prices went up since I got mine last year.
I had some of the cheaper lockers when I was a mechanic, they do what they should but I place the sentry way above them.
I do plan to build a spot in my house for a real heavy solid safe, I want to make it so it is near impossable to remove and it is protected except for the door that has to open.
Till then the sentry makes me plenty happy, and while not as good as some of the bigger safes it also did not cost as much and is something I can move myself when empty.