On a CSI rerun last night they had someone use an empty 2-liter soda bottle as a gun silencer.
Would that really work?
Also, I’ve seen for decades that shooting through a pillow works as a silencer. Does it?
If so, why don’t gang members tie pillows to their guns when they go on a drive-by shooting? It would presumably aid their escape if the noise was reduced.
Yet, out of the hundreds of murders in this city every year, I’ve never read of a pillow being involved. Nor a bottle. Nor, for that matter even, a silencer. Are silencers just a writer’s device for spy fiction?
Probably because pillows are bulky.
The sound of a gun firing is caused by 1) the muzzle blast coming out of the barrel of the gun and 2) the bullet breaking the sound barrier.
Wrapping a pillow around a gun is going to do zero if the end of the barrel is exposed (and you need it to be). I am not sure what it will sound like if you stick a pillow to the end of the barrel and pull the trigger. Most likely, you will have a pillow with a hole it and a deformed bullet that doesn’t go very far. You certainly couldn’t use it if you actually wanted to shoot something else. It would probably still be pretty loud too.
The only type of gun that I know of that is easy to make a silencer for is a .22 pistol or rifle. Even then, it still takes time and materials and those guns aren’t very loud or powerful to begin with.
Let me offer a personal anecdote. At one of the houses I lived in during college a friend of one of my roommates told us that a 2 liter bottle duct taped to the end of a shotgun would work as a silencer. He was encouraged to demonstrate this (but not by me, let me go on record that I think amateur modification of a firearm in any way is VERY silly and dangerous) in the backyard and I would say that, if anything, it amplified the sound.
To answer your other question, silencers really do exist but they are generally illegal and hard to find. My father was a firearm’s dealer and we had an Uzi with a silencer when I was growing up. The silencer worked pretty pretty well although you could still hear the action clank when it cycled. It wasn’t as though the shot was truly silent, it was that it was pretty quiet and it didn’t sound like a gunshot anymore. You could probably shot it in a house without anyone outside hearing it.
Haven’t tried a 2-liter bottle, but a 20-ounce bottle will work as a silencer for a .22 rifle.
.22’s are the loudest firearms in the world, so your results might not be as dramatic for other guns. Definitely quite effective for a .22 though.
aren’t, dammit!
They’re not illegal, from what I understand, in certain US states all that’s needed is basically a one-time tax-stamp (I seem to recall $200 being the cost) to legally purchase, posess and own.
Haven’t been to California lately, have you? 
Definitely and explicitly illegal here.
As for the OP:
Sure, a 2 liter bottle will work as a silencer. About as well as saran wrap will work as a condom - not so much. For many of the same reasons.
In the CSI ep, it’s a 20-oz bottle, not a 2-liter one. don’t remember the caliber of the gun, though.
You ever price a good down pillow, fella?
Actually, I think the noise serves a clear psychological purpose. Gangs are basically domestic terrorists with a clear, if illegal, business model, rather than a sociological or political agenda. A gang’s goal is typically to instill fear in neighborhoods and keep the locals in check. A blast of machinegun fire from drive-by shootings basically announces, “We’re in charge.”
Driving around with fluffy, hypoallergenic pillows strapped to your weapons isn’t likely to help a gangsta’s street cred.
It’s somewhat more complicated. Yes there is a $200 tax stamp required to manufacture or transfer a sound suppressor and is required each time it changes ownership. It also requires registration with the BATFE which means an FBI background check with photo and fingerprints as well as approval from your county sheriff. And of course not all states allow you to own one.
This is not something to screw around with. Having an unregistered suppressor is as serious as owning an illegal machine gun. Do not consider doing something illegal like making an improvised suppressor.
Great. Next thing you know, the liberals will be requiring registration of ginger ale and pillows.
Dumb Question: Did the CSI bottle have an open end? Hate to sound ignorant, but those injection-molded bottles are rugged. I wouldn’t be comfortable firing a .22 into the center bottom of one.
Think California has stringent gun laws? Try Massachusetts.
Here you need a Firearms permit to buy any type of rifle (yes even a BB gun). The permit costs $100 and MUST be renewed every five years (and it is $100 every time you renew) and you have to go to your local police station (usually on a workday) where you get fingerprinted every time you renew. AND after all that hassle, this permit is NOT good whatsoever, at all, ever, so don’t even think about purchasing a pistol.
You want a pistol permit ??? (If there were a rolling on the floor hysterically laughing my ass off smilie this would be the spot for it).
Of course I never have inquired about the legality of buying a silencer in this state. Maybe it is possible. (This would be a great spot for a few dozen of those above-mentioned smilies).
Sorry for the rant. Guess I’ve been spending too much time in “the Pit”.
One thing that hasn’t been mentioned is that there are .22 rounds which travel at sub-sonic velocities which would eliminate one of the problems shagnasty cited.
Granted, a .22 round is not the macho destroyer that any gang-member, thug, miscreant would ever be caught using. But I’m sure it has its uses.
Actually, I think most of the guns gangbangers carry are .22s.
You know, I haven’t touched my old bebe gun in years. If I have time this weekend, I think I’ll go plinking in my backyard and maybe tell you how the 2-liter bottle thing works on an air rifle 
Some semi-auto assault rifles have a threaded barrel to attach a flash suppressor.
Screwing on a automotive oil filter (with the bottom drilled through with a hole just big enough for the bullet) would make an excellent cheap silencer.
WonJohnSoup
Actually I’m a big fan of the .22 round and 75% of all ammunition sold is .22 caliber.
Its “puny” reputation is undeserved and I think anyone who uses the expression “Hey it’s only a .22” is an accident waiting to happen.
Maybe it’s easier to stick a Mac10 into the bum of a Care Bear than worry about pillows.
Careful about that, even with an air rifle. There’s a guy who has a page detailing his interaction with the BATF when he tried to build a supressor for his paintball gun (CO2 power, fires gelatin-based balls at 300fps). Although it looked like there was no way it could possibly be used on an actual firearm they didn’t make any distinction.
Yes, both two-liter bottles and pillows make cheap silencers. The U. S. Army even teaches the use of the two-liters bottle in sniper school. As for pillows, they were once an often used device in organized crime murders. The typical MO was to have two guys, one to hold the victim and the other to shoot him using the pillow to muzzle the sound. The limitation of both is they are only good one time. The bottle once shot was worthless for any more use because the same reason that it muzzled the sound the first time,was destroyed in the first shot. The pillow, on the other had, could be repositioned but it normally caught fire from the original shot. But as it was normally only used at point-blank range there was not a need for any more shots.