Sound suppressors, or silencers as they are commonly called, are fundamentally simple devices.
On the other hand, modern suppressors are designed with cutting-edge modeling and computer similation technology. Why? In short, the legal restrictions on sound suppressors mean that American purchasers want top-level products. People don’t want a crappy product after filling out paperwork, paying a mandatory $200 tax, and waiting 6-12 months for the government to process the application.
Eventually, I’m going to make a post on improvised weapons and home-built suppressors. Of course, all of this information is just that: information. I’m not advocating building illegal weapons, or at least not before the zombies rise up and devour 99% of the population. At that point, the only law will be self-preservation. (You do know that I’m joking about the zombies, right?)
Anyway, there are problems with home-built sound suppressors. Yes, they are less effective than the professional cutting-edge modern suppressors, but that isn’t the problem. The real problem is that you can’t attach a home-made suppressor to a typical handgun.
First, most semi-auto handguns have a moving slide that encloses the barrel. There’s no way to attach a silencer without using a special, extended-length barrel. Yes, some modern handguns do have extended threaded barrels, but they are an extremely small minority of all handguns. Attaching a sound suppressor requires installing an extended barrel (easy if you can find one in the apocalypse) or modifying the gun, which is a difficult job without the right experience and machine tools.
Furthermore, almost all centerfire handguns are “recoil operated”. Basically, the gun barrel kicks backward for a small distance. Adding a heavy silencer to the barrel means that it won’t kick-back correctly and the gun doesn’t work. It stops being a fast-shooting semi-auto and becomes a single-shot weapon. To keep the gun functioning correctly, the silencer needs to be very light weight or use a Nielson device aka recoil booster. Recoil boosters are too precise for the average survivor to build at home.
Revolvers? You can’t suppress a normal revolver at all without extensive, special modifications. (The Russian Nagant revolver is a special design that CAN be suppressed).
This highlights one of the advantages of a 22LR (or other rimfire) handgun. They usually have extended barrels that protrude out of the gun and are not covered by a moving slide, so a silencer can be built directly onto the end of the barrel. They are are blowback operated not recoil operated, so they don’t need a Nielson device (recoil booster) to keep the gun working.
Of course, there’s no rule that says you have to suppress a handgun in a post-apocalyptic wasteland. Very, very few rifles are recoil operated. Rifles, on average, often fire much more powerful ammunition than handguns, which poses a different challenge to creating a silencer. In simple terms, more powerful ammo means a greater chance of an amateur silencer exploding like a balloon from the pressure. If the zombies are coming and you need to use a home-made silencer on a rifle, then it would be best to look for a rifle that uses handgun or rimfire ammo.