Please don't laugh at me! Well, you can; I'll never know! Anyhow, what is the difference between a machine gun and a sub-machine gun? Is it the physical size or caliber? All I know is a machine gun keeps shooting until all the "Bullets" are gone as long as you have your finger on the trigger. I've always wondered, so what better place to ask? Please be gentle on me; I'm very sensitive!
Thanks in advance. Jeff T.

__________________
Waiting For The Sun.

I could be wrong, but I’ve always thought of a sub-machine gun as a personal weapon that fires pistol cartridges (9mm, .45 ACP) and a machine gun as a crew served weapon that fires rifle cartridges (.30-06, 7,62 NATO, 8mm Mauser).

__________________
"I also cook."

Machine-guns use rifle rounds, .308-.30-06-.303 while submachine-guns use pistol rounds, .45acp- 9mm.

I think submachine guns are those used on submarines. Joking aside the term submachine gun is built to fire ammo that is smaller power than average military machine gun ammo. In other terms pistol type ammo.

Uzi - submachine gun

M60 - machine gun

__________________
BTDT, Got The T-Shirt

Technically speaking: Fully automatic weapons have only existed for just over 125 years. That was when Hyram Maxxim gifted the world with his invention. Dr. Gattling's post-Civil War invention didn't qualify as an Automatic weapon (and still does not!)

The pistol caliber full auto weapon didn't come along until late in WWI when the Italians (Beretta) invented a detachable box magazine fed machinegun the used the 9mmx19mm Glisenti round. It was intended for air-to-air combat. (that's around 1917-1918, Col. Thompson's wonderful little devil came along in 1921 in 45 ACP and other cartridges. The C-96 "Broom Handle Mauser, got a full auto update around 1930. The Brits had a 9mm full auto Lanchester. That the Germans called their verson the MP-40 (not to be confused with the MP-38 "Burp gun")

The Europeans seem to call them Machine Pistols, and the American's use the term Sub-Machinegun.

Just as WWII was heating up, a third class of select fire gun was developed, The Assault Rifle! These were not always full auto and used a cartridge more powerful than handguns but less powerful than main battle rifles and belt fed machineguns. The M-1 Carbine, MP-44, SKS, & AK 47 fall in this category as do very many more.

Sub Machine Gun, it originally an American term the many English speaking people use.

Ivan

A machine gun is a crew served weapon firing rifle rounds. A sub-machine gun fires a pistol cartridge in a personal weapon. A assault weapon fires selectively for a less than full size round.

Well, that makes sense, but I don't think I'd like to get shot by either one. So in a submarine, you shoot through the screen windows on the port holes.
I guess I was on the right track with the cartridge size.

__________________
Waiting For The Sun.

So what then, is a full size round, and what is an M16?

__________________
Wisdom comes thru fear . . .

NFA definition; The term “machinegun” means any firearm which shoots, ....automatically more than one shot, without manual reloading, by a single function of the trigger.

A submachinegun is a type of machinegun, usually shoulder fired and using a handgun cartridge. An example would be my Lanchester Mk. 1* made by BOSS.

Attached Images

Lanchester Mark 1-a.jpg (34.6 KB, 23 views)

So, not fitting either one of the definitions you cited, what’s an M16?

__________________
Wisdom comes thru fear . . .

Light Machine Gun
Squad automatic weapon - Wikipedia

__________________
USMC 69-93 Combat Pistol Inst.

An M16 is an assault rifle, as noted above. A fully automatic (or actually generally select fire) rifle firing an intermediate cartridge. Technically a more specific subset of machine guns.

I’m going with battle rifle . . .

__________________
Wisdom comes thru fear . . .

"Sub-machine-gun" comes from "Sub-caliber machine-gun"...

meaning a pistol caliber, as many above have noted.


However, a lever-action in 45 Colt is not a "Sub-lever gun". For some reason.

Its a sub machine gun when the machine gun calls in sick.

Oh, you'll know.

Har har hardy har har - YouTube


Sent from my motorola one 5G using Tapatalk

__________________
Slava Ukraini!

Machine carbine was the older British terminology, Maschinenpistole is the German term, also the Russian-PPSh M-1941, e.g. Sturmgewehr is German for "assault rifle"-Stg 44, firing a round shorter and less powerful than a rifle round but still in rifle caliber.
We all know that firearms terminology is never that precise, when S&W lengthened the case of the 38 Long Colt to add more powder and give it more power they called in-the 38 Special. In 1935 they introduced a round that was in a lengthened 38 Special case and called it-the 357 Magnum.

There are many debates about this terminology but it is safe to assume that a "machine gun", as such, is crew served and can and does fire rifle caliber ammunition fully automatically by holding the trigger. A sub-machine gun doesn't need a crew. A machine pistol is hand held, no shoulder mount. And a so-called assault rifle is "sub-caliber" only to the extent that it's caliber is not a large, long range caliber - it is not defined as having pistol caliber cartridges. That is an error. See below.

The ATF and the public do not always understand these distinctions.

The online dictionary definition of an "assault weapon" is "any of various automatic and semiautomatic military firearms utilizing an intermediate-power cartridge, designed for individual use". That is, however, a political statement because a semi-automatic firearm is never an assault weapon. An assault rifle or "weapon", if you will, is always fully automatic, select fire or not, namely, a hand held machine gun.

Not to belabor the point, but I must - the Germans introduced this terminology in WW2 with their Sturmgewehr 44. A "gewehr" is a rifle in German. As you might imagine, German being a colorful language in many respects, "sturm" translates to storm in English and the point was that firing this fully automatic rifle raised up a storm of bullets, a hail of bullets being a more accurate term in re the weather analogy.

Understand that the Schmeisser (named for the inventor) or Stg44 was literally the first successful assault rifle. It used what is called an "intermediate cartridge", currently think 5.56 NATO as opposed to 7.62 NATO (NOT PISTOL CALIBER!!!), it could fire fully automatic but could be controlled in the hands of a trained soldier, and was "compact", think M16 versus the full sized battle rifle of the same time, the M14. Although a select fire equipped M14 basically fits the definition, too, regardless of caliber.

Such a rifle is not designed for long range shooting but, instead, primarily for nothing further than than a few hundred yards. Beyond that we're talking standard rifle calibers for long range, from .308 to .50 caliber and everything in between extant today.

I hope that clarifies the terminology somewhat. Just remember that because a rifle is not long, sleek, and stocked with fancy wood but with black polymer it doesn't become an assault rifle due to its appearance.

__________________
Come and take it!!

Are those machine pistols then ?

In between the two you had things like the M1918 BAR that was used as a squad automatic weapon. It wasn’t crew served and was fed from a 20 round box magazine, but fired the then standard .30-06 round like the 1903 and M1 Garand.

It was superseded for the most part by the M14, only some of which were issued with the fire selector installed, and in very limited use the M14A1 which had a pistol grip, a modified in line butt stock and muzzle device to better control recoil in conjunction with a bipod and a fore grip integrated with the sling to perform the role of a light machine gun.

However, the M14, given its full sized cartridge and select fire capability, would still be considered a select fire “battle rifle” like the German G1/FN FAL/L1A1 and the German G3 and various CETME derivatives.

The FAL as originally envisioned would have used the .280 British cartridge (.280” land diameter, .284” or 7mm groove diameter) which was an intermediate cartridge with a 140 gr bullet at 2550 fps.

We went with the 7.62x51 instead (147-150 grains at 2800 fps) and forced it on NATO, then almost immediately started developing the 5.56x45mm round, which was arguably a bit too far on the weak side (55 grains at 3250 fps).

Now that we are finally going with a 6.8mm (.277”) round we’ve swung all the way back in the battle rifle direction with the hybrid cased 80,000 psi 140 gr bullet at 2950 fps 6.8x51 round from Sig.

We’re slow learners who like to repeat our mistakes.

How about a Medium Machine Gun? M1919 Browning machine gun - Wikipedia

__________________
USMC 69-93 Combat Pistol Inst.

A full size round is considered anything ~30 caliber or more, so 30-06, 7.62 NATO, 7.5x55, .303 British, 7.65x54, 7.92x57, 7.62x54R, 7.7x58 (7.7 Arisaka to some), 7.5x54 are but a few. Perhaps full power is a more accurate description, as the 7x57 is also considered a full size round, pushing 173 gr at ~2300 fps and 140 gr at close to 2800 fps.

The M16 fires what is considered an intermediate round, 5.56x45 NATO. Other intermediate rounds are 7.62x39, 5.45x39, 6.5 Grendel, 6.8 SPC, and 6.5x50 or 6.5 Arisaka if you prefer.

The M16 is classed as an assault rifle as it fires an intermediate round. Battle rifles fire full size rounds. Examples are the M1 Garand, M14, FAL, FN-49, SVT-40, Gew43, and the Hakim, to name but a few.

__________________
Release the Kraken

Getting back to the original question…

It depends on who is defining what. The legal definition of a machine gun in the US is anything that is full auto, no matter what cartridge it uses. Wouldn’t try to tell the ATF your full auto .45 ACP Thompson isn’t one, they will be upset.

In the practical world, SMG/true assault weapon (not the plethora of semi-auto wannabes), and light/medium/heavy MG is as useful as any system for breaking down the category. Add “automatic rifle” for the BAR, M14, HK91, etc. if you like.

__________________
Alan
SWCA LM 2023, SWHF 220

The third class mention was never called an assault rife.......That term came in the late 60's from other folks.

__________________
S&W Accumulator

As to "assault rifles".

A while back these were brought to our attention by our former Rez Fed.

__________________
Music/Sports/Beer fan

From my understanding, most 'full power military cartridges' through WW2 had to meet the universal standard of the day. That was to be able to disable a horse (cavalry charge or cannon crew) at a thousand yards/meters in volley fire.
For convenience, almost all machine guns at the time fired the same round as the infantry rifle.
Battlefield tactics changed dramatically after Korea. A lot more was learned during Vietnam. Our military is still evolving into a new cartridge/platform.

__________________
Chris
SWCA #2243 SWHF #292

The OP was afraid of laughter at his question. I am reminded of an old saying that is as true as a mother's love.

There is no such thing as a dumb question, however they are a trainload of dumb answers.

My posts and questions had a purpose, which everyone here should internalize. This thread has demonstrated why we as pro 2A persons have such a difficult time conversing with anti 2A persons. We can't even agree on terms amongst ourselves . . .

__________________
Wisdom comes thru fear . . .

You've never sat in the last hour of a training seminar before lunch or before the close. There are absolutely stupid questions . . .

__________________
Wisdom comes thru fear . . .

Or at the very least, totally useless questions. True that.......

A whole class of weapons has been left out of this discussion. That is the Insult Rifle. There are many in this class regardless of action.