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Wednesday, August 29, 2012

Ballistics Question

How many inches of poured concrete is suitable against .50 BMG?

Many variables, obviously. Consider a few shooters lobbing rounds at a poured concrete house. Residents inside need some time to gear up and form a counter, Is 6" of poured walls going to hold off .50 BMG? 8"?

The object of the exercise is to thwart a sniper with thermal capability. If the sniper locates his Target we don't want a single round taking our target out.



  1. Go to the tables at the bottom of the page here: http://www.inetres.com/gp/military/infantry/mg/50_ammo.html

    Appears 2" of concrete is enough.

  2. NO! 6 inches WILL NOT stop a .50BMG More than 1 time in 4. The japs in ww2 judged 16 inches of steel reinforced concrete was a minimum. The germans in ww1 and ww2 thought that 4 in. was the thinest you cold use in a front line shelter, and that was only for a .30cal. hit . That was a "splinterproof". An M-1 garand or a M-1903 with M-2AP ammo will cut a 2in concrete wall in 6 shots. If you plan on gettin' jackhammerd by a .50 ya' best be buldin' you a THICK bunker wall.

  3. Raufauss has better penetration and is supposedly more accurate at long range than ball or AP ammo.


    Also, the chart linked by Bonnie Gadsden claims one shot of 50 BMG ball ammo will successfully penetrate 2" of concrete at 200 meters, but less than that from farther out. I would anticipate AP or API possibly beating that. I would want at least 6-8 inches of nice hard low-slump concrete between me and somebody shooting at me with a 50, and still plan on that being a temporary shelter at best.

  4. The sneaky trick for a wall is to fill it with gravel. Then you can't just pound a hole in it with a rifle because the gravel keeps filling in the spot. The gravel eventually will all spill out from a big enough hole, but it takes time - which is what you need.


  5. About 4" should be good


  6. Also, you should check out Insulated Concrete Foam (ICF) constriction if you haven't seen it before. Foam blocks get stacked like lego blocks then filled with concrete. The foam is left in place to serve as insulation. The concrete can be up to 11" thick and the forms are flexible enough to even do curved walls. 11" of steel reinforced concrete is fairly substantial. The foam is easy to work with and very suitable for "amateur" construction, although the concrete pour needs to be professionally monitored.


  7. Someone sent me this link:

    It takes 300 rounds (of .50 BMG) to penetrate 2 meters of reinforced concrete at 100 meters.” *

    *An Infantryman's Guide to Combat in Built-up Area, field manual 90-10-1, US Army, May 1993.

    So, I guess not too much but not so little...




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