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View Full Version : What´s the difference between machine guns and cannons?



GreyBeast
12-24-2004, 11:55 AM
Ever since I´ve played Il-2 about two years ago I know about machine guns and cannons.

But just recently I asked myself what ACTUALLY distinguishes them. Does anyone know?

ddsflyer
12-24-2004, 12:10 PM
Simple, machine guns fire solid bullets, cannons fire explosive shells.

oFZo
12-24-2004, 12:15 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by ddsflyer:
Simple, machine guns fire solid bullets, cannons fire explosive shells. <HR></BLOCKQUOTE>

Doesn't the size have anything to do with that too?
Would a 155mm solid projectile be fired by a machinegun or cannon?

Cajun76
12-24-2004, 12:16 PM
http://www.geocities.com/CapeCanaveral/Hangar/8217/fgun/fgun-in.html

http://www.quarry.nildram.co.uk/WW2guneffect.htm

http://www.quarry.nildram.co.uk/ideal.htm


The main divergence I have heard is caliber, and I believe is generally thought that 20mm is the transition. Early Fw-190's had a mix of HMG and cannon 20mm, IIRC. This is not absolute, and there is always strong debate over effectiveness, practical applications, usefullness and results, among others when talking about guns, ammo, and fighters. Hope the links help. http://forums.ubi.com/images/smilies/16x16_smiley-happy.gif

Cajun76
12-24-2004, 12:20 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by ddsflyer:
Simple, machine guns fire solid bullets, cannons fire explosive shells. <HR></BLOCKQUOTE>

Really? So the 37mm on a 'cobra is a MG whan an AP is chambered, but a cannon when a HE round is loaded? Same goes for the 30mm HMG on the late Bf-109's too when the AP rounds are fired? Also, there were HE .50 cal rounds, so my Jug can have 8 cannons! http://forums.ubi.com/images/smilies/16x16_smiley-wink.gif

Von_Zero
12-24-2004, 12:36 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR> Same goes for the 30mm HMG on the late Bf-109's too when the AP rounds are fired? <HR></BLOCKQUOTE>
mk 108 has no ap ammo, only Minnengeshoss and HEIT http://forums.ubi.com/images/smilies/16x16_smiley-indifferent.gif

Cajun76
12-24-2004, 12:47 PM
http://forums.ubi.com/images/smilies/1072.gif http://forums.ubi.com/images/smilies/10.gif 2 out of 3 points ain't bad, is it? http://forums.ubi.com/images/smilies/16x16_smiley-very-happy.gif

SUPERAEREO
12-24-2004, 01:33 PM
AFAIK Cajun is right when he mentions calibre: by convention anything 20mm. or above is classed as a cannon, but some countries (Japan?) have used different classifications at some time in history.

S!

pain.......
12-24-2004, 01:34 PM
yes, caliber decides if a gun is a machine gun or a cannon.
but I believe that 15MM was a minimum caliber for a gun to be called a cannon.

JG52-6High
12-24-2004, 02:19 PM
http://forums.ubi.com/images/smilies/351.gif

>15mm = cannon (agreed by most people), no matter what kind of ammo is used.

6

BuzzU
12-24-2004, 02:29 PM
I also agree that 15mm starts to be a cannon. Although a weak one.

VW-IceFire
12-24-2004, 02:57 PM
Somewhere between 15mm and 20mm the cannon becomes distinguished by machine gun.

Also, the useage of explosive charges in the shells is also a definition point.

But it also depends on the nation in question. The Japanese put explosive charges in a 12.7mm machine gun (I think). So is that a cannon? Maybe!

If its 20mm, you can be fairly sure it called a cannon. But as far as I know, its a language thing rather than a clearly demarked reason for it. I mean, the German's primary 20mm cannon for most of the war was just an upsized 15mm "machine gun" (or cannon! http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif).

Its confusing...

Old_Canuck
12-24-2004, 04:33 PM
Ah yes, very good post and replies. I came in here expecting to see some interesting ideas from the prophead professors and you didn't fail. http://forums.ubi.com/images/smilies/25.gif

tttiger
12-24-2004, 06:00 PM
It isn't confusing at all.

If it's .50 cal (12.7mm) or smaller, it's a machine gun. If it's larger, it's a cannon.

It has nothing to do with exploding shells. Some countries, Italy for example, had exploding .30 cal rounds but that didn't make them cannon.

It's an arbitrary but generally accepted dividing line based entirely on caliber. If you want to be generic and call them all "guns" you will be correct as well.

Here's the best web site I've found on aircraft armament. Interesting reading:

http://www.geocities.com/CapeCanaveral/Hangar/8217/fgun/fgun-in.html

Hope that helps.

ttt

GreyBeast
12-24-2004, 07:18 PM
Ok, lots and lots of information. Thanks. My conclusion is that 15 to 20mm is the threshold for machine guns (smaller caliber) and cannons (larger caliber).

The point made about cannon rounds containing explosives and machine gun rounds being solid is interesting, though.

Happy Christmas, everybody!

LStarosta
12-25-2004, 08:21 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by GreyBeast:
The point made about cannon rounds containing explosives and machine gun rounds being solid is interesting, though.
<HR></BLOCKQUOTE>

That is a really bad point. As others pointed out, some cannons fired solid armor piercing projectiles and some machine guns fired explosive projectiles.

Chuck994
12-25-2004, 09:59 AM
There is an interesting article in the september issue of Aeroplane (www.aeroplanemonthly.com (http://www.aeroplanemonthly.com)).
Machine gun versus cannon, A rain of blows or a knockout punch. This should give you some insights into the differences between the two.

Blue skies, Chuck994

georgeo76
12-25-2004, 01:39 PM
I don't believe the distinction is technical, just descriptive.

the word 'cannon' was first used to describe a particular type of naval artillery. It was then adopted to refer to all types of these weapons. Since then, it's used to describe any large gun.

sauron6
12-25-2004, 05:13 PM
Well, HE is considered effective in 15mm or larger. 20mm even. The effects are very minor compared to even 15mm HE, in 7-8mm and 12-13mm.

Daiichidoku
12-26-2004, 12:59 AM
IMHO, the real difference is that a machine gun is made to fire continuously, automatically

A cannon does not necessesarily have to

Of course, calibur size plays aprt, too, but AFAIK, there is no definitive criteria that sets these firearms apart

chaikanut
12-26-2004, 03:07 AM
Cannons are distinguished from machine guns due to their calibre: Anything below 15mm is a machine gun. 20mm is the minimum caliber from which explosive packing becomes efficient. I believe that use of automatic cannons solely against personel is prohibited by the geneva convention, along with poisoned , incediary or explosive bullets of any caliber (or anything else that causes ''undue suffering'').

MO_JOJO
12-26-2004, 03:34 AM
This is more complicated than I thought. A MG does not fire explosive ordnance, or does it? Someone mentioned .30 HE rds, but I would like to see that for myself. That is pretty **** small, and what kind of fuse did they have? I know the US has an infantry weapon (MK-19) which fires 40mm HE and other type belt-fed shells and yet it is called an MG.

I think Daiichidoku has made a valid point as well. A cannon can fire a single rd., (but so can the M2 .50 cal infantry version), so does it also have to do with how the weapon is loaded, i.e. cannon being non-linked ammo, vs. MG being belt-fed? I believe caliber is a determining factor, as well as type of ammo, and the firing mechanism of the gun.

Can anyone confirm or refute this?

chaikanut
12-26-2004, 03:46 AM
Like I said, the distinction between the two is only calibre, nothing else. Machine gun can fire explosive or incediary rounds but in terms of sheer energy and ballistics, those are less effective.

SkyPiggies
12-26-2004, 12:07 PM
Duh... simple

Machine guns go rat-tat-tat

Cannon go pop-pop-pop