Guns / weapons choice questions

What are the advantages of a sub-machine gun like the H&K MP5 over a pistol like the Beretta 92?

Wouldn’t a 9mm pistol have the same firepower, and be easier to handle?

In a real life situation like, say, a home invasion gone bad, and SWAT had decided to go in, why would the team equip SMGs rather than pistols? Or would they use a different weapon altogether?

Forgive me if these are naiive questions, but I’m curious.

Jeff Cooper is not a fan of sub-machine guns, but I once read where he thought it might be the best tool when you have many individual threats in close proximity (e.g. twelve bad guys sitting around a table).

Fired in controllable burts, the machine gun probably increases the ‘knock down’ percentage.

The problem with pistol cartridges like the 9mm is that they have a low first-shot knock down percentage. The movies distort the lethality of such guns, by showing the good guy kill people right and left with single shots. In the real world, many people have been shot with a 9mm and continued to fight. I remember reading one case where a coked-up maniac jumped on a cop, and at point-blank range the cop unloaded his entire clip into the guy, who proceeded to jump up and run away. He died eventually of blood loss.

Also, the SMG carries more bullets, which would be useful when you’re trying to clear buildings of terrorists and such.

An aimed shot from a smg would likey be more accurate, since there would be a greater distance between front and rear sights.

Better range, better accuracy, better rate of fire, more ammo. Pistols are… well, not toys, but they’re good only as backups, or when you can’t (or don’t want to) walk around with something heavier.

Thanks for the responses.

Follow up question: Do cops ever use SMGs on the 3-shot burst setting? I thought they only ever used single shots.

well, this is a total WAG but from playing games like counterstrike where the weapons are based on real life weapon effects, the MP5 is better if you are surrounded & need firepower. It also can work medium distances in single shot fashion.

So, as i said i’m guessing here, there are 3 ranges. Far range, medium range & short range. An MP5 would offer an advantage if targets are in short range (due to increased firepower & 30 round clip), and perform slightly better in medium range due to more control over the weapon.

Over the ranges on a home entry this would be irrelevant. Aimed shots at a distance outside of 30-40 feet this would become an issue. Point shooting is standard method for this type of situation so the sights are not used.

Pistols are also lighter and easier to manuver in tight quarters.

SMG’s in single shot mode are only fractionally better than pistols except for the larger magazines. The ability to deliver a “lead shower” is a nice bonus for many situations.

Another reason that SMGs are a better shoice in certain situations is that, for the same ammo, the bullet will have a higher muzzle velocity (and therefore higher kinetic energy) coming out of the longer barrel of a SMG over a handgun.

The reason is as follows (simplified):

  1. The velocity of the bullet is due to the acceleration created by the force of the expansion of the gas created when the powder is ignited.
  2. This acceleration will continue as long as the gas is still expanding in the direction of bullet travel.
  3. When the bullet exits the barrel, the expansion of the gases no longer travels solely in the direction of bullet flight, so the acceleration (for all intents and purpsoses) stops here.
  4. Kinetic energy is proportional to the square of velocity. (KE=.5*V^2)

Since the barrels are not long enough for pressures to equalize, each added inch of barrel length will afford some additional muzzle velocity, and energy.

I assume the barrel of an SMG is rifled. Therefore the longer the barrel, the more spin is generated on the bullet. I presume this is another reason why the accuracy of an SMG is improved.

I can see your point about muzzle velocity, good explanation.

My question still stands about whether police ever make use of the 3 shot burst option, or if they only ever use single shot mode. Hmm… I saw badge on earlier, he may open this if I’m lucky!

Wouldn’t it then be called a “rifle”?

The reason why most people dont own machine guns(and anybody could have owned one prior to 1934) is because machine guns have very little practical use. Machine guns never did really sell very well in this country - few people bought them.

Machine guns are great in war, esp if the troops did not grow up with guns and cannot hit their targets very well with a regular gun - thus the saying: “spray and pray”, (hoping one of the bullets from your machine guns hits someone, or at least scares them).

Machine guns are great if you are being attacked by a hundred people charging you, but other than that, you will miss more often than hit your target, and you will waste a lot of bullets.

I have shot a dozen different types of machine guns(go rent some different ones and try it for yourself). They are fun to shoot, but I would not choose to keep, own, nor carry one for self defense.

If I “had to have” a machine gun, it would be the uzi, because it is the easiest to fire accurately.

Of course, I grew up with guns, and I can hit what I am aiming at with a regular gun, so I dont need a machine gun.

Susanann, I’m talking about sub-machine guns here. Proper machine guns fire a much more powerful round, don’t they?

Also, you sure about the Uzi being the easiest to fire accurately? I’ve never fired one, but it looks like a pray-n-spray gun?

SPOOFE: Sorry… I was talking about the grooves inside the barrel that make the bullet spin, giving it more stability. Maybe I used the wrong term. Love your username by the way!

Samarm The grooves inside the barrel are refered to as rifling - you are correct in that. However the length of the barrel does not impact the amount of spin. The amount of spin imparted is determined by the number of “twists” or rotations per unit length of barrel. Most firearms (excluding shotguns) have rifled barrels - including rifles, handguns, and SMGs.

Again, you are correct that machine-guns typically fire a higher-powered round. The submachine gun was designed to fire pistol ammo. That’s why many now are chambered in 9mm. Other popular calibers are .40 and .45.

I would also join you in questioning the accuracy of the claim of the uzi being the most accurate SMG.

I am not an expert with machine guns. I have shot a whole bunch of them, and I know what I like, but that is all.

To answer your question: I dunno, I am not sure what a “sub-machine gun” is, but the last place where I rented machine guns, advertised: “stop by and shoot a live sub machine gun”. I rented quite a few different kinds.

I guess they had machine guns, and sub-machine guns, they shouls know what a sub machine gun is since they are a gun store and they should know about guns, and what they are called.

I know the m-16 felt like a Matel toy, and it rose too much when I fired it - the first shot would be on target but the succeeding rounds would shoot higher . (Maybe if I practiced with it, I could learn to handle it better)

The Thompson machine gun was way too HEAVY!

The smaller “handgun” machine guns were too hard to fire accurately, and keep on target.

I always hated the uzi, because it was UGLY! I didnt even want to shoot it, but I did, and I was quite surprised!! It was amazingly accurate. It had a lower rate of fire, and was better designed, it did not rise like most machine guns- I could keep the sights on target of full auto very easily. I could hit everybody I aimed at, if I could find enough bad guys to shoot at.
Here is the list of “sub-machine guns”(???) I shot at the last place I rented them at:

Thompson m1a1.45
Suppressed m11/9mm
m3a1 greese gun .45
uzi 9mm
h/k mp5 9mm
sten mk ii 9mm
m-16 9mm
madsen m50 9mm
mp40 schmeisser 9mm

What I am saying is that the rate of fire was “slower” in the uzi, plus the recoil of the gun was “straight back” so the barrel did not rise for successive shots, I could keep all my shots in the black with the uzi, even shooting the entire clip. It also “seemed” light(maybe I picked it up after shooting the Thompson - I dont remember, but anything after the Thompson would seem light), and confortable to shoot. (it is still ugly though)

Therefore, I found the Uzi to be the most “accurate” (for me) of any machine gun I have ever shot, and the one I would choose to carry if I have ever found the need to ever carry one.

Something doesn’t quite sound right about what Susanann has posted. Anyone here know a lot about guns, care to help me out?

Does the M16 chamber a 9mm cartridge?

Is 600 rpm in the (slowest firing) Uzi considered slow?

Is a sub-machine gun a compact auto weapon chambered for a pistol round?

“Rifle” has a legal definition as well as meaning spiral grooves in a barrel. A rifle is a long arm with a shoulder stock. A machine gun is a different animal legally speaking and is not a handgun or a rifle no matter what its configuration. It may or may not have a buttstock and has no minimum required barrel length as a rifle does.

FWIW I’ve had some opportunity to shoot a Heckler and Koch MP5K PDW competetively so I’ll throw my 2¢ in. It’s essentially an MP5K with a folding buttstock. The owner had it setup with a special trigger pack that has positions for safe, semi-auto, two shot burst and unrestricted full auto plus an ambidexterous selector like the “navy” model. The two shot burst position is extremely effective. A single trigger squeeze reliably puts two shots on target. Three shot burst packs seem more popular but the third shot is often wasted, missing over the target because of muzzle rise. It’s an extremely quick handling weapon and works well for me but has some drawbacks. The ergonomics are outstanding except for the selector. Because I don’t have freakishly long thumbs I can’t reach the selector in safe mode so I start each stage with my thumb on the right side. The other drawback is the H&K roller block design is extremely finicky and sensitive to dirt. It works beautifully when clean but has been balky at times. Last time I shot it I got a fired case stuck in the chamber despite H&K’s special fluted chamber. I spent a good 20 seconds pounding the bolt handle to get it out which cost me several places in a match. If I was in a real firefight it would have cost me much more.

If the shinola hit the fan and I had to depend on an SMG for my life it would be the Uzi. It may not be as elegant as the MP5 but is far more robust and reliable. It fires from an open bolt so it’s not a super precision benchrest rifle but it’s not supposed to be. It has effective accuracy for it’s intended purpose. Also the rate of fire is slow enough that it’s easy to get single shots even in automatic mode. I can do the same with the H&K but because of a much higher rate of fire it’s fairly difficult.

Jeff Cooper is absolutely right about “spray and pray” being ineffective. What I’ve learned from using these things in competition is “he who shoots the fewest bullets wins.”

Strictly speaking no but the M-16 is a very modular weapon which can be converted to multiple calibers. The upper reciever which has the barrel and sights can be separated from the lower reciever which has the magazine well, trigger group and buttstock in a matter of seconds. A change in the upper reciever/barrel assembly along with the bolt carrier plus an adapter to use 9mm magazines can convert an M-16 to be a 9mm carbine. AFAIK the military has never used these. Most of the conversions use modified Sten gun magazines that have a cut to allow the M-16 magazine catch to work. Colt does make 9mm carbines but the magazine well is permanently converted to use their 9mm magazines.

Pretty slow as subguns go.

More or less. The term was coined by John Thompson for his namesake weapon. It pretty much means a machine gun with a shoulder stock in a pistol caliber. There are true machine pistols, a Glock and the Beretta 93. I’ve seen someone try to use the Glock machine pistol in competition and it proved itself to be possibly the most useless weapon ever made.

according to what I’m finding on google, it’s 5.56mm.

Well, it’s slower than many SMGs, but I don’t know if i’d describe it as particularly slow. It’s still ten shots/second.

I’m no expert on guns, but I’d say that’s pretty accurate. It’s compact, but not pistol sized or anything. Full autos that are pistol sized are called autopistols, I think.