I don't know about the stone in the wall cavity trick. For the price of these building materials it might be better to construct reinforced concrete block walls, cheaper materials and less labor involved. I know for certain that an armor piercing 7.62 round (designated by a black tip) would penetrate. Also, I have seen several marines shot dead who were standing behind a sandbag wall and the Russian 7.62x39 RPD machine gun rounds went clean through the sandbags as well as the marines. You need a full 4 sandbags of wall width to stop bullets. All Russian made AK47, SKS, or belted MG ammo fires bullets made with a tungsten core and these are to be considered as armor piercing ammunition.

Actually, Mr. Skousen is right about the walls constructed with his methods absorbing bullet hits. The stone and gravel will cause the energy in the bullet to radiate outwards in cone fashion into the stone and gravel. 7.62 NATO is probably correct for the most that could be stopped, anything larger is likely to completely penetrate and cause serious collateral damage from the cone spray of rocks and rock parts. His method is to spread the energy of the round over a large area which really does work. That energy is reduced considerably dependent on the area it is spread over. Larger area much less energy, smaller area concentrated energy. That is why I recommended placing a sand barrier between the metal plates and the back wall, that sand will absorb a HUGE amount of energy.

I have already gotten some negative feedback from people I trust on what I am about to write so take my words with a grain of salt but I finally purchased The Secure Home by Joel Skousen and read all 700 pages. He has come up with a wall section for taking multiple shots from 762nato and claims it will withstand it and keep you secure. The wall is to be framed ONLY with 3.5" metal studs, 3/4" plywood on the exterior side, 1/2" or 5/8" (or both together for soundproofing) on the inside, fill the wall with 1" stone and finish the interior in drywall and the exterior with foam board, waterproofing and whatever finish you want. He claims nothing will come through this wall as the stone absorbs and destroys any projectile. He suggests people use this for their secure space in existing basements or use this method under porches or whatever application you want. He also states you can use this to build you entire home with or especially recommended for the bottom four feet of any new construction home. I was pretty excited until I received doubtful feedback from two people that I trust.

That steel, it is definitely useful at the homestead as armor for the walls, windows and doors. Depending on thickness, it could very well stop or seriously slow projectiles enough to neutralize that threat. Place it at as much of an angle as you can against what you are armoring and the thickness increases greatly depending on the angle. A 1/2 inch plate could equal 4 inches at the right angle. Put up a back wall behind it and fill the space between plate and wall with sand for even more protection. That's a lot of work though.
Food is also rather high on my list of necessities and I pick up more from time to time. I'm going to be concentrating a bit more on medical necessities for awhile and more construction hardware and bits when I can. I have lots of bits and pieces so more is just insurance and, when I disassemble abandoned structures, I'll recycle/repurpose the fasteners in those structures. Good thing I have too many hammers! :lol:
I'll also remove and store piping, wiring, shingles or other roofing materials, the cabinets, doors, furniture, fixtures and pretty much everything in them if I am able. Of course, I'll have to use the first structure as a storage building for all the goodies I'll be totin' over to the house. Put the dog to work haulin' some of it, she'll be handy at that.

I think about that kind of thing but it is not high enough on my list. Food and such seem to stay at the top. I have purchased a lot of tools from flea markets and auctions. My better half is starting to say how many of those old hand tools are you gonna buy?? But when I see any that do not require power...I can't seem to resist and typically no one else wants them. Also have a good selection of all types and sizes of shovels, picks, saws, rakes, and planet junior gardening tools. I already have a large supply of construction materials and hardware taking up space all over but I truly never thought about taking it with us. Your post is going to make me look at all of this stuff and reevaluate WillyPete. We also have several sheets of steel of a variety of thicknesses that we should probably toss onto the floor of our trailer. The only thing is...will we have power or not? If not...what can we do with sheets of steel? I know...put them up at every opening!

I think if the future comes at us that Rawles wrote about, we will all be facing the decision that you mentioned. If you have a real need and there are abandoned homes all over...well that kind of clarifies what to do.

I've been occasionally adding to my stockpile of nuts, bolts, washers etc. and picking up pipe, lumber, wire and other items so that I will have some materials for repair and/or renovation of the buildings on my lot. Stuff's gonna break down over time and having a method and materials to keep the outside out and the inside in is a fair good plan.
I also have knowledge of where materials can be obtained even after a major catastrophe. Figure the neighbors bug out and do not return for years and years, or longer, there are copious quantities of building, shelter and construction materials to be had for just the work necessary to get them from the other buildings over to yours.
Some may question my ethics in this case, I am thinking that if the place is abandoned and noone claims it over a period of years then, it's abandoned and open to whoever then lays claim to it. This is, of course, an open statement as there are too many variables to take into account for what may happen so, there will be no "hard and fast" rule regarding abandoned property.
Comments ad opinions are a good thing. Who knows, we may even reach an accord about this very topic.