I have fired a heck of a lot of ordinary rounds through cinderblocks. Were the blown through bullets still terribly dangerous? Oh, sure, they would draw blood and possibly cause death or serious injury. Do you want to know how to be the most conscientious about shooting in a room that may have cinder block walls and may have people on the other side? High velocity and light weight lead to break up and deformation against hard surfaces such as a layer of drywall and two layers of concrete mix. A heavy bullet of greater sectional density, fired with similar energy levels, will be more likely to pop through the things instead of turning into spall within the first few inches.
What are the chances that a standard handgun round of .355 or so diameter will poke its way through a cinder block wall, retain a lethal amount of energy, and actually strike and kill or seriously injure a guest in the other room?
My god, that's slim. The chances of a gunfight inside a hotel are pretty slim. I've worked at hotels and never had it happen. The chance that a round will strike the weak section of the block are maybe one in four, the chance that the round will be able to punch through with lethal energy remaining is getting pretty near ridiculous odds, and the chance that a stray round from a hotel gunfight could do all of those things and still hit someone in heart or cns and actually penetrate to a dangerous depth are maybe getting into the area where you might die in a shark attack. What makes the whole debate kind of screwy is that may never find a multi story modern hotel with cinderblock walls. And there, right there, you have the most questionable thing of all. How often will a person be in a situation that would actually have that risk? Most likely, only within the home. Depending on the home, the location, the chances of hitting a bystander or sleeper in another home is still really slim. Can a bullet really go through two layers of outside wall and maybe interior walls after dodging cars, utility poles, furniture, appliances, etc, and still manage to hit one of the small number of small targets there and cause potentially lethal injury?
Will buckshot go through a block wall? Depends. If you fire at point blank range, ten feet for example, almost certainly. That stuff hasn't had a chance to spread, you aren't hitting that wall with a bunch of scattered lead pellets. That massive wad of lead pellets will dust right through the first layer. A great deal of the energy will be expended dusting the concrete and smashing the pellets, so it may be stopped at the second layer, or it may penetrate so ineffectively that it won't even draw blood. How would I know? I've never tried it. But we are still looking at the same run of probability. the chances of a round of buckshot putting a lethal hit into a person on the other side of a wall borders on absurd.
There are plenty of multi story apartment buildings still going up on wood frames, one is being built just a few miles from here.
There's always a chance, however slim it is, that a magic bullet will go through kennedy's head, a piece of the car, connelly's leg, a secret service agent's wooden leg, and still be found a mile away stuck in a phone book between the Bs and the Ss. A person should still take the responsibility to minimize those risks and not deliberately arm himself with weapons like the 88 magnum.