View Full Version : Uneven 8" concrete block walls and ricochet

November 16, 2006, 10:08 AM
I'm finishing up our basement for my wife to use as a studio (works at home), and I'm evaluating a new defense firearm purchase (any excuse ;-).. Previous work location was suitable for just about anything due to firing angles but I'm a bit concerned about ricochet from the very uneven block walls.

They 're being covered by 2x4stud walls (2 walls insulated) and 1/2" drywall which perhaps would be enough to catch anything that might try to bounce off?

It seems to me that shotgun in general would be very resistant to ricochet of any sort, and handgun cartridges (in a carbine perhaps) should be okay? Of course large caliber rifle might just punch in, but if the bullet hits at an angle I could see a possible problem.

I don't want this to turn into the 'best home defense gun' type thread, just looking for input on caliber/type choices for a room built outta concrete block...


November 17, 2006, 02:02 PM
Hollow 8" concrete blocks or solid concrete blocks?

Last time I shot plain old 8" hollow blocks my 9mm punched right through with ease as expected.

They will hold up well with a lot of pressure bearing down on them from above, but give them a whack from the side and they crumble, got yelled at for that one time, was 10 and had a hammer. It doesn't take much to bust them.


November 17, 2006, 02:58 PM
Use a frangible ammo, then you dont have to worry about bullets bouncing all over the place and they have plenty of stopping power.

November 18, 2006, 08:17 AM
good for target practice...bad for self defense.

November 18, 2006, 10:42 AM
I standard hollow concrete block, you won't hav a problem with ricochets. I've shot a few 4" and 8", and even solid block....The concrete will usually break and contain, but anything that does bounce off has lost almost all of it energy, and would probably barely make it back through the drywall. Actuall, rifle rounds are safer, as they are mor likely to break into the block and stay there.

November 18, 2006, 10:58 AM
If this is going to be a stay at home weapon for access in the studio...why not a shotgun? I don't think you should be that worried about ricochets. Bullets have a mind of their own..99 times out of 100 something we expect might happen...then that one time it's just a freak of nature.

Do you just want to have a good excuse to buy a new firearm? :)

Capt. Charlie
November 18, 2006, 10:00 PM
The study of bullet ricochets is a complex science in and of itself. We can predict trends in ricochets in general, and sometimes probable outcomes, but the variables involved are so great and sometimes complex, that a predictable, accurate outcome is rarely possible.

Consider this abstract by the US Dept. of Justice on an article published in the Journal of Forensic Sciences in 1992.

Annotation: The urban environment provides many surfaces from which bullets or shotgun pellets may ricochet, and factors determining whether ricochet will occur include nature of the target surface, angle of incidence, shape of the projectile, and projectile velocity.

Abstract: Research on the ricochet of bullets and shotgun pellets indicates that surfaces have a critical angle of incidence below which projectiles will ricochet. Bullet shape and makeup determine whether the bullet will ricochet in a given situation. Low velocity projectiles are more likely to ricochet than high velocity projectiles, and angles of ricochet are typically low. The angle of ricochet increases with increasing angle of incidence; the angle of ricochet is generally lower than the angle of incidence. Although attempts have been made to produce a mathematical model of bullet ricochet, the bullet's trajectory after ricochet is generally impossible to predict in any detail. Bullets may tumble after ricochet due to the change in orientation of a spinning projectile's axis produced by collision with a surface. When shotgun pellets ricochet from a surface, the pellets will spread out parallel to the surface. Bullets and shotgun pellets lose energy when they strike a surface, but they retain enough energy after ricochet to inflict serious or even fatal injuries. When police officers investigate shooting incidents in which ricochet has occurred, they should pay special attention to the nature of wounds suffered by shooting victims, bullet or shotgun pellet deformation, presence of trace evidence, ricochet marks on surfaces, and ricochet geometry. 27 references and 4 figures

Throw the word "uneven" in the mix, and you have a mathematical nightmare. I understand your concerns in wanting a predictable outcome, but be aware that Murphy's Law has a huge influence here ;) .