mm Vs Cal.

See T&T forum

In the United States, we traditionally use "Caliber" for the size of most guns under 1 inch (25.4mm), and just inches for anything bigger, like 16 or 18 inch guns on a battleship (roughly 406mm and 457mm guns respectively).

The caliber/calibre measures the bullets diameter, so .45 Cal is about 0.45 inches in diameter or 11.43 millimetres. The American M16A1 fired an .223 caliber Remington cartridge, the 3 part being sort of a business thing... lol. In metric, the M16 family fires a 5.56x45mm round, currently the M855 round (more widely known as the SS109 around the world) which is an improvement over the type of 5.56x45mm ammo U.S. troops used in the Vietnam war with early model M16 rifles.

5.56x45mm = bullet diameter x cartridge length in millimetres

basically, 5.56mm thick and 45mm long.

The .50 Cal Browning equates to a 12.7mm diameter killer, most of which are somewhere between 3 3/4 and 4 inches long, thus the: 12.7x99mm anti-whatever-ales-you round :-). (Yes I'm to lazy to do the exact conversion lol.) I remember one retired solider who said installing M2 .50 Cal Browning heavy machine guns on tripods with sandbags, really discourages helicopters from landing on you -- and I believe him lol.

How powerful the bullet is depends on a lot of things. When you pull the trigger, a hammer or striker essentially ignites a priming charge firing the bullet out the muzzle at high speed; a rifle is called a rifle because the barrels "spin" the bullet with rifling. That spin helps the bullet retain it's intended path and gives you more accuracy then you can get with a smooth bore. Muskets and virtually all cannon-like artillery in the old-old-old days were smooth bore weapons; (generally) all shotguns and some Artillery pieces still are.

That bullet will spin cutting through the air, head downrange, and really reach out and touch someone; you get slammed with a small fast moving projectile that is usually designed to either penetrate your body leaving a nasty wound channel, or to quote a funny movie error: stick in you and raddle around forever like pac man. How hard, fast, and where it hits depends on many factors, see Ambu's post about JBs question yesterday.

It's more effective to leave the enemy with wounded men then dead men. Because that's more enemies you can wound while they try and pull their mates out, and that's more wounded men to tie up their resources.

The characteristic "drop" of bodies and such when they get shot on TV, is not death; it has to do with the bodies response to being shot. If you are still standing and the bullet goes through you, what is there to stop you from continuing the advance? Nothing really: that's why some people fire a burst into the persons chest, then depending on what is more available - put a follow up shot between the eyes, effectively cutting off the brains ability to do anything, or put a bullet into your pelvic region, in such a way that it is meant to cut out your physical ability to keep walking towards them (and hurt like a son of a gun). Pain and damage of the bullet is not always a reliable way to put someone down, using medical science in your favor is.

I think Ambu, Medic, or En4cer would be more qualified to explain the effects of a gunshot wound.... so I'll shut my mouth on that part lol.

Put a few bullets through the terrorists brain, and they will be dead shortly. Put a few in their chest and the shock of being shot might put them on the hard deck; best put a few in their head afterwords to make sure they can't flip a grenade behind your teammates backs I.M.H.O.

footnote: I've never fired a rifle in my life

When assessing the likely severity of gunshot wounds, there are numerous variables which include the following, considered either singly or in concert:

the particular type of weapon used; rifles are generally more destructive than handguns. For example, a close-range abdominal wound inflicted by a 7.62 NATO rifle will be much more severe than one inflicted by a .38 revolver from the same distance.

the calibre of the weapon; e.g. a wound from a small diameter bullet will generally be less severe than a wound inflicted by a larger diameter when the velocities are the same. The cartridge designation is generally an approximation of bullet diameter and is of value to the gun knowlegeable in estimating other characteristics; velocity, weight, design, etc.

the design of the bullet used and its velocity. Expanding bullets are more damaging than non expanding. Of the non expanding bullets, flat or very blunt nosed bullets are more damaging than more pointed bullets as the more pointed bullet may push some tissue aside. Heavier bullets will penetrate more deeply than lighter bullets at the same velocity.

the range at which the victim was shot; i.e. wounds inflicted from a distance of 5 metres will invariably be more severe than those fired from a range of 500 metres if all other factors are equal. The velocity of a bullet (and therefore its destructive potential) gradually reduces as it travels from the muzzle of a firearm.

the path of the wound. Initial entry is a poor guide as it is only a single point.

the number of wounds inflicted. Frequently, gunshot wound victims have been hit multiple times. For example, being hit once is less severe than suffering four separate wounds. In much the same way, an individual pellet from buckshot is comparatively small, though since victims are usually hit by large numbers of pellets simultaneously, the degree of injury is severe, particularly when the wound is inflicted at close range.

Even non-fatal gunshot wounds frequently have severe and long-lasting effects, even after the victim has made a successful recovery. Typically, the consequences involve some form of major disfigurement and/or permanent disability. As a rule, all gunshot wounds are considered medical emergencies which require immediate hospital treatment.

Excellent Answers, very interesting post!

I suspect Gun enthusiast are not so much concerned with the exact size of the bullet, more for the damage it does...but very interesting post none the less...

did anyone actually state the obvious? In Europe we using the metric system..therefore the calibre of our weapons are measured in millimetres.
In the US they still use imperial measurement..so the calibre of American weapons will most commonly be in inches.
For Example...
German made USP pistol = 9mm
American made Colt pistol = .45 inches

The term caliber refers to the diameter of the round this does not include the brass casing.

so like the major said .45cal = 0.45inches

mm is straightforward enough. Just that americans like to be a little different to the rest of the world.

So my rifle carries 5.56mm NATO round. What is that in Caliber ?

Hi carter,

below you find some usefull links to your question:

1. Shotgun shells:

Link: http://en.wikipedia.org/wiki/Shotgun_shell

2. Amunition (cal. and mm)

Link: http://de.wikipedia.org/wiki/Liste_Handfeuerwaffenmunition#B.C3.BCchsenmunition

or

Link: http://en.wikipedia.org/wiki/Table_of_pistol_and_rifle_cartridges_by_year

Regards
Hunter

Americans ARE a bit different than the rest of the world. Heck, our country is so big that Americans are a bit different than other Americans.

Carter, the question of which caliber cartridge has the most stopping power is a perennial one in gun circles. Everyone has their own "religion" about it. You can pretty much count on an annual article in gun magazines titled "9mm vs .45cal"

It's also like picking a hammer. "Which one is best?" Well what job do you want to do with it? Professional assassins choose the .22 LR round, way down in the small end of cartridges, for close in kills. Yet at close range it's highly effective to the skull and easy to silence. If you want a home defense shotgun you go with an 18" barrel for manuverability but as a duck hunting gun....good luck. On the other hand, your duck gun would be a bitch to use indoors.
The effectiveness of any firearm is related to the situation/purpose it is to be used in/for. In addition, a longer bbl may change the ballistics of a cartridge, altering it's velocity due to burn speed of the POWDER type and quantity.

One more factor....the speed with which multiple rounds strike the target. After a very short period of time, the body shuts down and minimizes the shock value of any rounds striking afterward. This leads to the classic 9mm rounds split personality. In a SMG on full auto with a longer barrel, it is highly effective vs live targets. On single shot or from a shorter barrel (such as a pistol) it's effectiveness in STOPPING a target is significantly reduced...barring head shots. Thus the Mozambique Fire Drill...2 to the body, one to the head (which is also the cure for a body armor.

Congrats, you have entered the hornet's nest of "which is best" but you have started with some good information above.