fortifying a wall

[rockriver]

i'm helping build a metal building. (sort of a chief go-fer)
26 gauge walls.
so, a discussion came up about bullet penetration and how to make part of the wall secure so that a .22 .223 or x39 or xxx wouldn't penetrate.
this is a steel frame structure. we commonly call them butler buildings in our area.
there will be some interior walls. maybe 1/2 plywood... maybe 1" rough pine...
so this siding discussion encouraged the opinions on which would stop a round. and would added layers of plywood/pine boards give any protection.
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what say ye? comments? suggestions?
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I just went to a certain web site where they test some items. dagnabit. I was impressed.

[Lowdown3]

It would take a heckuva lot of pine or plywood to give you any real protection.

Even a 4' concrete block stem well with the steel building anchored on top of that (Quonset hut style) would be good. You could pour the 4' wall solid with grout mix and rebar.

Testing at the Lowdown3 residence shows that this will stop .308 at 15 yards with no problem.

[Bill Foster]

Back in the 80s, when Lowdown was in elementary school��, I would practice at a nice indoor range in the cold weather. There were two lanes for hunting rifles, which meant 30/30, 223, 308 hunting rounds, no AP. Nothing hotter. The owner had a pre-trap on those lanes made of sheets of 3/4 plywood that held 18” of gravel in between. It was to slow the rounds before they hit the plating. During hunting season, the plywood was replaced weekly and the gravel was shoveled back in. That stuck in my head.

[cpt_sfc]

Pea Gravel , spreads the impact more. Also depends on make up of the pea gravel,(kind of rock its made of) It also falls back to fill temp cavity caused by rounds hitting. Test out a ply wood box box full, it should be about 2-3 bucks a bag to test but get it by the truck (yard) for the actual use. About 6 inchs thick.

[1Admin]

The pea gravel thing is a decent fix. To fill most conventionally framed wall cavities (2x4 construction), would mean about 3 1/2" nominal inside for filling space.

2x6 framing wouldn't leave that much more either- about 5 1/2" nominal space for filling.

For an after the fact type of deal, I think people would be better suited to filling sand bags and placing them inside large chest of drawers, etc. and using them inside the house for points of cover. Put them in place before filling.

All of the residual 5 gallon buckets and 55 gallon drums we would be (slowly) emptying post apoc could be used inside dwelling spaces and filled with earth to create small cover spots.

You will need to know how the home is constructed. Slab on grade would be perfect. Wood framing over a crawl space or basement would require more work, perhaps some additional supports and/or bridging.

I wrote a piece about this for Rawles blog about 12 years ago, it's been copied around the net since.

[rockriver]

cpt, admin,
2 great suggestions and posts. thanks
in our situation. purlins (horizontal metal framing 4 ft off ground)
are 8" wide. giving some room for modifications.

[protus]

If space isn't a consideration I'd go solid poured block.
But an alternative is to solid full wall is to build a solid half wall.
Allowing for cover but cutting cost etc.
Of course this means anything above that point is still not safe.
Those walls could then if wanted be filled with gravel,sand etc .
Just a matter really of how much protection you wanted and how long you wanted it to last before being defeated.

[cpt_sfc]

Protus, I have to disagree on the poured wall, it would give a more solid barrier BUT , It's weakness is it is solid. A AP 7.62 will go thru a block wall filled with concrete. but 8 inchs of pea gravel will stop it. Plus cost is a factor. Also as it the, (solid), pocks , it weakens it with every shot. I used to build rifle and grenade ranges for the army and have fired a lot of different ammo at things. Sand bags are ok but bags of pea gravel stop more. Weak point is the container. 3/4 ply would be a good backing and sheets of horse mat in front would cause the bullet to yaw and be stopped easier. Anything in front of the pea gravel to cause yaw would help. The pea will also cause yaw as is. Also stopping shrapnel is different then bullets in a lot of ways. Both methods are easy to test out. Cost would be about 20 bucks to test both.

[rockriver]

thanks cpt!