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Material to put in walls to reduce penetration

Discussion in 'General Gun Discussions' started by Fryerpower, Feb 15, 2013.

  1. MattShlock

    MattShlock Well-Known Member

    1/2" armor plate steel. Try changing guns and ammo instead. And ignore the 12 ga. "birdshot is great close up" mumbling...
  2. 481

    481 Well-Known Member

    And extremely well at that.

    In this US DoD publication


    there are equations that will allow anyone interested to explore the resistance of common building materials to small arms fire and residential bricks seem to be one of the best options.

    According to the equations found in Chapter 5: Building Elements- fired residential brick (not veneer) just 1.25 inches thick will defeat the 9mm M882 (1275 fps) while 7.5 inches of the very same type of brick will defeat the M855 round (~ 3050 fps) and 8.5 inches will defeat the 7.62 NATO M61 (~ 2800 fps). Most bricks are 3.5 - 4.0 inches wide so it'd take just one extra layer at the front exterior of a building to greatly improve its resistance to small arms fire. Easily done during or after construction.

    In comparison, according to the same publication's equations, it takes 5.5 inches of kiln dried pine to stop a 9mm M882, nearly 10 inches (9.75 inches) to stop the M855 round, and 14.5 inches to stop the 7.62 NATO M61 round. That's a lot of wood.
    Last edited: Feb 16, 2013
  3. wep45

    wep45 Well-Known Member

    concrete and rebar
  4. hueyville

    hueyville Well-Known Member

    All of these steel, concrete, etc recommendations for a remodel situation are non workable as the weight will compromise the.structure. There are over a dozen companies making a fiberglass composite material that can be purchased from NIJ level II through level IV and beyond at reasonable prices considering what it does. Cheaper than hard plate steel and 25% or less comparable weight. I am hesitant to recommend a particular company but a Google search will find this product. Three of the bigger more reputable companies are located in Texas and the best I have used actually is made just a few mileage from me in N.E. GA. They can be sawed with a blade comparable for ceramic tile. The product is outstanding and easy to use. A previous poster mentioned using it in Judges benches. Almost every judges bench built in past decade has this material so judge just has to duck and he is bullet proof. It can be sawed with correct blade, drilled and screwed. Easy to use and Detroit existing structures. Steel is not bullet resistant till you move ul to T1 or AR400 hardplate. Then its heavy and if you cut it using heat it can compromise its reliability near the edges where it was heated.

    Now as th HDPE, I use this product weekly. I buy it buy the pallet load in thickness from 1/4" to 1.5". It will stop lower velocity pistols with large frontal diameter. A civilian 5.56 will burn though 1" and have seen SS109 penetrator burn through 3" of this material. Concrete and rebar is good but you can't pour concrete into the walls of your house. Unless you are doing new construction it is prohibitive in a remodel scenario unless you had this planned already. I bought a home that had to be gutted and redone. Thus, since I had the drywall ripped out I bout enough of the fiberglass type panels already cut to 14.5" with and.put them between the studs on from and sides of house. The parts without brick are rated to stop up to .38/9mm. The brick areas will stop more.

    Too many people over or under think the subject. Everything you need to know is readily available on the web or from companies that make these specific materials. Like 1/4" Lexan will stop a 38 special but if it is less than 20 degrees Fahrenheit it will not stop a thrown rock. As mentioned before my basement walls are 10" poured concrete with 4" thick red brick. I found a piece of 10" thick concrete from a construction demo and placed.some 4" red brick in front of it. I was happy with what it would stop. I have also taken 1/2" mild steel and seen how easily it was to blast holes through it. 3/16" AR400 will stop what 3/4" mild will not. Math, physics, etc tell you all you need to know.

    When you consider concrete there are as many formulations as there are in steel. I have a friend who specializes in selling hardened concrete for secure facilities such as government and bank vaults. Concrete is not all the same. So there are so many variables in hardening a structure no matter the material that there is no easy answer. The newer laminated fiber products with kevlar layers embedded are the lightest, easiest to install and toughest out there. My clients use all according to project. I see it all as part of my business is to install faraday cages to protect.from EMP events and electronic surveillance. I have to work with the companies that do the blast/ballistic/storm protection on a regular basis. Solutions that cover all of these are way more complicated than a little steel or concrete.
  5. Skylerbone

    Skylerbone Well-Known Member

    20 degrees F would be awfully cold for an interior wall. Any approximation on cost of specialized panels? I'm starting to think I should do a little more remodeling.

    MICHAEL T Well-Known Member

    1/2 thick Lexan will stop a lot of common pistol ,shotgun and maybe 223 Not cheap . I used thinner in my store. Behind windows to stop smash and grab and all my jewery show cases was built using it. To prevent robbers from busting case and grabing jewery .
  7. Fryerpower

    Fryerpower Well-Known Member

    Panels like you described built into or attached to bookshelves would do the trick with no gaps. Or bolt to the walls and then put bookshelves in front to hide them.

  8. rodinal220

    rodinal220 Well-Known Member

  9. Hunter125

    Hunter125 Well-Known Member

    What if you tore out one side of drywall, then fixed steel luveres between the studs. Same concept as an angled steel target. Maybe the cavities could be filled with something to catch bullet fragments with sheet metal over the studs to contain ricochets.
  10. LeonCarr

    LeonCarr Well-Known Member

    I still like the idea of the Quilt/Tapestry hung on the wall with Kevlar panels attached to the back of them.

    Granted unless your nickname is "The Quilt Guy" it might be hard/weird/cost prohibitive to cover all your interior walls with Quilts and Kevlar panels, but you could use the concept for specific walls or a safe room.

    All of the other great ideas in this thread IMO would work better with a remodel or new construction, when the Quilts and Kevlar panels would involve hooks screwed into studs on your existing walls.

    Just my .02,
  11. Shadow 7D

    Shadow 7D Well-Known Member

    Insulated foam form concrete...
    With a nice brick exterior
  12. Arp32

    Arp32 Well-Known Member

    For an interior wall?!?
  13. michaelbsc

    michaelbsc Well-Known Member

    Oddly enough the entryways at my house are both enclosures from earlier entryways, so there is brick inside the foyer.

    I don't think this is what the OP is getting at though.
  14. CountryUgly

    CountryUgly Well-Known Member

    Easy fix.... large book cases filled with books. I have several placed through out the house in areas where I don't want to overshoot (see kids rooms).....
  15. hueyville

    hueyville Well-Known Member

    We continue with the Lexan recommendations. For those that are recommending it I would like to know how much of it you have actually shot and with what? I pulled a piece of 1/8, 1/4, 3/16 and 1/2 scrap out of the rack just today because of this thread. We cut and clamped them into the bullet trap and chowed down. The person that thinks it "may" stop 5.56 might want to give it a try before making that statement. Even the half inch was defeated with .45 acp hardball. Didn't even have to magnum size a pistol to defeat it. Same with HDPE. 1/2" and under is not a reliable bullet stopper. If it was, you would see it marketed as such. One of my suppliers sells bullet resistant clear polymer materials. The thinnest product they have in the catalog that is rated to stop "most" handguns is 1.5" thick. It has three layers laminated together with the outside layer being designed to be a U.V. blocker and scratch resistant.

    I have 1/8" to 1" Lexan, HDPE, Plexiglass and others in my materials rack. In our steel rack we have aluminum, stainless steel, mild steel, T1 and AR300 and a few scraps of AR400 hard plate. 3/16 to 1/2" hard plate will stop most handguns. Full magnums will bust 3/16" with a full perpendicular strike. At 30 to 45 degree angle it becomes much more resistent to penetration.

    Back around 25 years ago I built my first set of falling plates out of 3/8" T1 steel. I had them for several years and shot them with every handgun I owned. As they were designed to tip when hit and the T1 is relatively hard I never had a problem. One day I happened to have my AR-15 practicing some 3 gun work. It was loaded up with 55 grain jacketed soft points. I decided to run it across my falling plate setup. I ran it across the plates and two failed to tip over. I could not believe I missed so I shot at each again and they quivered but didn't fall. I walked down to the plates and everyone had a nice little hole burned right through the middle and the two that didn't fall had two holes. Had to bring them to work and weld up the holes with a hardening rod.

    As I mentioned earlier I have a center storm window in all of my homes windows made out of 1/4" Lexan. The outer storm windows have 3M Ultra Prestige Security Film over tempered glass. Then the center frames have 1/4" Lexan and the actual windows are standard double layer glass insulated windows of a slightly better grade than in most common homes. I have actually shot at a real simulation of my windows. A lead 38 special target load does not make it completely through first shot but everything is fubar. My goal for my window setup is to stop debris in the even of a tornado traveling in close proximity to my house slinging crap.

    Lexan also if used in direct exposure to sunlight loses most of its toughness within a few years. In cold weather it is fragile. Too many better products. My house is an older house and in the remodel process we bricked it over. Masonry is the easiest and cheapest fix for exterior walls. If your worried about interior walls and shooting through an hitting other family members you have a couple of easier fixes. Don't turn an AR-15 loose in the house. A riot 12 gauge with 2 3/4" buckshot rounds will stop the bad guy without going through him, the wall and your kids. YMMV,
  16. dirtykid

    dirtykid Well-Known Member

    Now you guys got me thinking,,
    I sell galvanized sheet-steel for HVAC duct work,up to as thick as 18ga,
    I would think a layer of 18ga steel witha layer of 1/2" sheetrock, then another layer
    of steel with a final layer of interior 1/2" sheetrock would slow down just about any
    small-caliber round to the point where it would no longer be deadly.
    I will make such a wall,and test it when the weather calms down,
    In theory , even a FMJ bullet hitting a layer of steel,with a dense material like sheetrock
    behind it,supported by another layer of steel,would bring velocities to less than lethal,
    Having the bookshelf full of books would be an excellent insurance barrier to stop shrapnel,, I normally sell 4'x8' sheets of 18ga steel for $39 a sheet
  17. Skylerbone

    Skylerbone Well-Known Member

    I don't think anyone is proposing Lexan by itself. The OP is using a carbine for HD and believes any armed intruder will likely be carrying a handgun. What was proposed with Lexan was, from his room toward kid's room: 1/2" Sheetrock followed by air space followed by 1 3/4" of wood (common stud), sandwiched to 1/2" Lexan, sandwiched to 1/2" Sheetrock. No claims have been made as to effectiveness but the OP is planning to mock up any setting before demo begins.
  18. 481

    481 Well-Known Member

    That's an interesting approach.

    Using the building material penetration formulas found in this publication-


    -a 9mm 115 gr FMJ @ 1155 fps would exit those materials at 350.4 fps and a .45ACP 230 gr FMJ @ 850 fps would exit at 232.5 fps.

    Using the Schwartz bullet penetration model found in this publication-


    -the 9mm 115 gr FMJ would still penetrate to a depth of 10.1 inches in soft tissue after exiting those materials and the .45ACP 230 gr FMJ would still penetrate to a depth of 6.6 inches in soft tissue.

    Add another 18 gauge steel sheet (a third sheet) and neither round should exit (at least according to the formulas) the barrier.
  19. brboyer

    brboyer Well-Known Member

    Experienced shooters know that many handgun rounds penetrate more in typical home construction than does .223

    Same with buckshot.
  20. Skylerbone

    Skylerbone Well-Known Member

    And hopefully home owners choosing a .223/5.56 for HD aren't shooting steel core ammo as was cited in posts. I have serious doubts an intruder would be, unless they're from the Government...and not there to help.

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