I read your blog every day and enjoy finding information that is useful. Recently a posting discussed the use of the 5.56 mm NATO bullet and its poor performance in penetrating automobiles.
I took notice of this information about the penetrating power or lack of penetrating power of the 5.56 in relation to single and double barriers.
We moved onto our five acres of land nine years ago. One of the first building projects was to have a contractor installed tornado shelter set in the ground. Then over the next two years I added a 16’x20’x50” high system of concrete walls around the opening to the tornado shelter. I added baffled entrances and a sturdy roof. The concrete walls are 7 inches thick on the bottom and taper to 5 inches at the top.
I designed this kind of wall to get the greatest thickness on the bottom where any residual radioactive might collect on the ground.
On top of the concrete walls is a 24” tall wooden wall with screened openings 7” along the three sides away from the embankment. The insides of these walls are stacked with bricks to increase the personal protection factor (PFC) against radiation and perhaps the penetration of bullets, slugs and shot.
We have electricity and water in the bunker. The roof has survived a single impact of large hail that we measured at 3.25 inches in diameter. Thankfully we had this hail only fall for 30 seconds and it was spread out widely on the property. One of these large hail stones penetrated completely through our house roof. But I had sheeted the roof of the bunker with 3/4 inch plywood. We call this structure our "Weather Bunker."
I have proceeded to attempt to harden it against weather and other possibilities. The south side of the weather bunker is protected by setting 9 to 11 foot tall discarded electric line poles along the roof edge. They average 8 to 11 inches thick and extend up to the roof ridge in height. I get these discarded poles from the local electric company. The north side and part of the east side are protected by a row of railroad timbers set on end creating a wall. These are for breaking the wind and protecting the shingles on the roof. However they do present an initial barrier for bullets, slugs and shot before coming to the concrete wall. We have a 350 gallon water tank on the north side that sets outside. This barrier protects it from visual observation and perhaps from penetration from light firearms.
The weakest part of the structure are the two doors made of 2×4’s and 5/8” plywood.
Recently we replaced our heat pump and the contractor left the old unit. During the disassembly I discovered that the outside was made up of two louvered rectangular units curved around to encase the unit. They laid out nearly flat when removed. They are good heavy steel units. After measuring I mounted these plates on the outside of the two doors. I now have a louvered steel plate plus two layers of 5/8” plywood on my doors. We will be visiting the contractor who did the installation looking for two more from discarded units for the inside of the doors.
As I read this article about penetration of the 5.56mm NATO I realized that the addition of these louvered plates was the correct thing to do.
We are both 72 years of age. Unless there are some really severe mitigating circumstances we will not be leaving this place if all hell breaks loose. This place is our lifeboat. But we are surrounded by hundreds of acres of range land. Some of which is very rough hilly land covered in sandhill plum brush, sages brush and some shinnery oak. The larger draws support a surprising growth of larger trees.
We have developed rally points close and far. Under certain conditions if we were forced to take to the land we have an environmental set of conditions in which we could hide. We have one ATV to use for transport locally in the rough land. As a last resort we have two pneumatic four tired garden carts that could be pulled. If the situation deteriorates we plan to buy another ATV of some sort quickly.
We have had to adjust our outlook recently. My wife had a mild non-debilitating heart attack last year. She is back to normal now. I appear to be recovering from Leukemia after diagnosis in January. Time will tell us how our health is and time will mark the requirements for our survival.
My thesis for this note is this: you should consider these louvered air conditioner plates as additional potential barriers for doors, windows and walls. They should be available if you can find the contractor who has a junk yard full of old units.
Secondly consider using railroad ties or discarded electric line poles for barriers around your retreat or home. Don’t forget to put a barrier around your outdoor privy area. Nobody wants to get shot with their pants down.
From the red hills of western Oklahoma and America’s most secret redoubt. – Joe C.