silencers or suppressors as they are now generally called have a number of uses and limitations.
a suppressor
but also
3. can dramatically reduce muzzle velocity and hence the range and stopping power of a bullet.
to be used very effectively an integral silencer is preferable ie mp5sd using a closed bolt operating system.
also reduced charge within the ammunition is sometimes necessary to achieve the desired effect.
p.s unlike in the films the effective range of an mp5sd is near to 20 metres. so a silenced weapon is only useful in certain situations
Possible for some weapons but even so a wooden bullet will have far less mass than a lead/copper one so recoil force will be negligible.
and
Yes, in some suppressor designs but this is the exception rather than the rule. Many integral suppressors are baffle jackets wrappped around a barrel riddled with vent holes. This will give somewhat less velocity than an unvented barrel of the same length but keep in mind an H&K MP5K only has a six inch barrel and typical pistol barrels are an inch shorter and they have effective ranges of fifty yards or more.
Some suppressors use wiper type baffles which actually contact the bullet but these are very unpopular. While they are very quiet they destroy accuracy.
Contrary to popular belief rifles, even with supersonic ammunition, can be effcively suppressed. There may still be a sonic boom shock wave but suppressing the muzzle blast and flash can coneal the shooter’s position. I’ve seen a .308 bolt action rifle shot with a suppresor and standard high velocity ammunition (about mach 2.3 or over 1,750 miles per hour) and the noise was tolerable enough we could listen without hearing protection even under a shed roof.
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While you’re all here, can I ask what the difference is between a machine gun and a submachine gun?
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As I understand it, and I’m sure someone will clarify better shortly, a Submachine gun is for individual use hand-held, while a machine gun is larger and usually on some kind of a mount or tripod/bipod.
A machine gun fires rifle (long and pointy) ammunition, while a sub machine gun shoots pistol (short abd stubby) ammunition. Also, MGs are usually much bigger.
The term was coined by John Thompson for his namesake invention. He defined it as a compact machine gun in a pistol caliber designed to be fired from the shoulder. That last bit it an important distinction as there are guns such as they Beretta 93R and Glock 18C which are automatic and in pistol calibers but not submachineguns. They are also incredibly stupid ideas but that’s just MHO.
The legal definition of machine gun in the U.S. is extremely inclusive as it is any gun that will fire more than one shot with a single pull of the trigger. In many cases a single part such a reciever or auto sear is a machine gun in itself.
BTW, the compactness of the whole gun has nothing to do with its classification. A Thompson is considerably bigger and heavier than an M4 or AK-47 for instance.
It’s a continuum Kalashnikov. Granted the Tommy gun has extremely heavy construction but it’s compact compared to standard military shoulder weapons of the day. Sturmgewehre such as the AK-47 and M4 didn’t come long until decades later. Besides, Mattel® wasn’t around in the '20s to set the standard in lightweight military weapons 
I’ll have to put my M4gery on the postal scale for grins as it’s a real featherweight. Note: I will not be doing it at the post office.
LOL
Elethiomel: precise placement of rounds on any part of a target, using a suppressed weapon chambered for a pistol cartridge, is very real-world. The Heckler & Koch MP5SD mentioned by Padeye and others is the world standard for clandestine/stealth operations. The 9mm round it fires is more than adequate to the task for which it is employed. Keep in mind that other, less potent calibers such as .22 LR and .25 ACP have been successfully employed in close-range encounters of the violent kind. One of the many important considerations for using suppressed firearms is the ease of communication between team members during an exercise.
All this is true. However, I mentioned time constraints - for instance, say you’re a trained special forces kind of person. During a stealth mission you turn a corner and contrary to what the intel people said there are two enemies there. They see you. Suddenly you have very little time in which to neutralise both these targets. Now, do you go for the risky head-shot, or do you put three-four rounds in each of their relatively large, easy to hit torsos?
I’m not saying that precise placement with sound-suppressed weapons isn’t plausible, I’m saying that in many situations it won’t be practical to make that one-shot-one-kill headshot.
Dunno how relevant this is, but the ‘Bren’ machine gun was too accurate when it was first invented, i.e. several bullets would go through the same hole (waste of bullets). For this reason a sort of a cone was stuck to the end of the barrel (with the flared end pointing in the direction you were shooting in), which meant that each round took a slightly different trajectory. Less accurate, but more effective…
I’m afraid you need to provide a cite for this one, since IIRC, the cone is a flash hider, and I’ve never heard of any army needing a weapon that was less accurate.
“Suddenly you have very little time in which to neutralise both these targets. Now, do you go for the risky head-shot, or do you put three-four rounds in each of their relatively large, easy to hit torsos?” - well, sir, I contend that if you have enough time to put out, “three-four rounds” on each target, you probably have time to instead place one decisive, well-placed shot in each target wherever you choose. If you anticipate what elevation you expect your carefully placed shot to occur, you are way ahead of the curve, too. By the way, I can think of at least one firearm that a “dispersing device” was used on - the .50BMG M2 HMG.
Suppressors for firearms are not designed to be fired at the full cyclic rate for an automatic weapon for sustained periods of time.
Many commercially available suppressors are good for perhaps a full clip worth of slowly fired ammunition before heat and/or pressure fatigue will negate the effects of even a wet suppressor. All suppressors need to be regularly maintained or replaced to maintain safe firing conditions. A full out burst of even subsonic pistol ammunition would rapidly become unsilenced as well as wildly unaccurate. Not that SMG’s are widely known for match grade accuracy.
Secondly, many Hollywood used firearms are modified with extra light springs that allow blanks to cycle the actions without frequent stoppage. These movie guns would also become unsafe if fired with real ammo.
As with any firearm of any type, safety should always be the first concern.
I contend that placing three-four rounds on each target’s torso using burst fire is considerably easier than placing one round on each target’s head in the same time. The head is smaller and moves around more violently, especially in a situation where the target is surprised and reacting to some important stimuli (like for instance seeing an armed stranger suddenly turn the corner).
I think non-shooters underestimate just how fast and accurate a skilled shooter can be. FTR I consider myself pretty good at action shooting but am by no means a top shooter. A really good shooter can easily knock down eight head-size falling plates in 2-3 seconds. Navy SEALS, Army Rangers, etc. are not wanna be, sideways-gun-holding, gang bangers, they are the cream of the crop.