Ron, you are correct about having the flat area that surrounds the foot down onto the rear base--that is very important. The feet touching the barrels on the bottom is unwanted, BUT get it as close as possible, including contouring, so that it is as strong as possible in resisting upward prying forces during recoil, which is where I have seen one fail.
Concerning the fitting of the slide, here is my concern: human perfection not being a possibility, design it so that, as Mike said, it pushes down on the foot. How? Well, since there are tolerances involved in the fit of the slide to the horizontal slot it moves in, something has to "take up the slack" of those tolerances, or it isn't really tight. I decided it should be the slot that forms the top of the feet. I angled it EVER so slightly "uphill". As it is polished, it gets really tight just as the slide is coming to the end of its travel. In fact you have to give it a push to complete the travel. A wear mark on the side of the rear base conveniently showed when the slide had maxed out. It may be that Mike's plan is better on several accounts and less risky. But if I were to adjust the slide instead of the slot for the feet, I would STILL adjust it at a slight, slight angle in order to tighten up. A perfectly level slot is probably not a possibility. Even if it were, the area that sits down on the top of the base probably wouldn't be perfectly leveled, and that would tilt things. The slide is microscopically loose in its groove. And even if everything were perfect, by the time you got the slide to move over the perfectly level foot, it would not be pushing down with much force AND WOULD NOT GET TIGHTER, since it would slide across at a straight angle. I want it to unmistakably get tight! 25-30% of the claw mounts I have inspected on guns were a bit loose if you took the time to lift up on the rear of the scope--they moved! And of course to varying degrees. The first I saw was on a spankin' new Mannlicher Schonauer back in the late sixties. The person who had shelled out a wad of bills for those days was so upset he returned it to the vendor. So if you are going to err, err on the side of things getting progressively tighter. We are not talking about the kind of angles that will lock up after recoil, especially if nicely polished to fit. Steve PS...I don't know how to do pictures yet.
