Afterwards you are always smarter - this is the case with us, too.  Since the first version had included some typos and other mistakes here the revised (and hopefully) correct article about Shadowrun weapons and real calibres.

The initial version wrongly assumed that light pistols used the calibre 9mm Para. This lead to a wrong judgment of the other calibres. Since the standard calibre for SMGs is 9mm Para and probably will be for some time in the future (especially concerning UZI SMGs) and since the calibre diameter and jouledata of 9mm Para more likely resemble 6M than 6L (6L would be much too low for the characteristics of a 9mm P.) the assumption 6L could be 9 mm Para must be wrong.

This indicates that there are no 9mm Para Pistols in the Shadowrun-Universe (=>Pistols having a 6M Basedamage). A new conclusion for us, too.

The problem in judging SR-Damagecodes in conjunction to real calibres is the following:
The SR-Damagecode displays the damagelevel and powerlevel - this could be called manstopping-effect. This is very useful for the game but places a great difficulty regarding the comparison to real calibres. This is because the physical data of real calibres can easily be measured but the manstopping-effect is not as easy defined.

Nobody can predict the entire effect of a bullet regarding a living target since every living target would react somehow different. This incorporates the "human" factor which is unpredictable.

A different opinion we are always confronted with is:
Lots of people assume that the Ruger Super Warhawk is a .44 Magnum Revolver. To explain that we have to take a wide turn:

Our opinion is the following - The SR-Damagecode 9M reflects the calibre .45 ACP or .40 Smith & Wesson. Why?

1. The first SR-Weapons were "created" around 1989. At this point was .45 ACP still the calibre for military pistols, that's a fact (measured by US standards). 9 mm para, at this time the standard calibre for SMGs was not typical for pistols (even the first modern SIG 220 was available only with .45 ACP). The big boom of  9mm pistols started only much later. Since in the US the .45 ACP is still very popular and meanwhile becomes even more so (even as calibre for SMGs) the assumption can be made that the regular damagecode for heavy pistols is displayed by the popular calibre .45 ACP.

2. A .45 ACP calibre pistol can still be constructed to fire bursts without rupturing it through the explosion pressure. Additionally the gun won't wear out as fast and therefore does not require that many repairs. A gun that can't take the pressure and where its parts have to be replaced continuously wouldn't sell very good, ain't that right? The Bren Ten pistol made by the famous pistol marksman Jeff Cooper used the calibre 10mm Auto. The project flunked because the 10mm Auto proved as "gunkiller" and this without burstmode. The bigger the calibre the more metal has to be put around the bullet by the designers  (you get the picture) to prevent the gun from exploding. Imagine the strain increase on the gun if you want to fire a burst instead of a single shot.

3. If you look at the statistics of each calibre it seems logical that .45 ACP / .40 S&W is 9M, even if you think of 9mm short as 6L and 9mm para as 6M (what appears logical because of the E0). The next highest calibre of 9 mm para would be 7,63mm Mauser. After this there would be .40 S&W and .45 ACP already.
After showing why .40 S&W / .45 ACP is 9M we can now concentrate on the initial question:
Why is 10M not .44 Magnum?

If you look at the E0-Stats of .45 ACP and .44 Magnum you notice that the difference between them is
674 Joule (!). This is more than the average E0 of an 9mm Largo. And the Shadowrun-Damagecode is only raised by 1 point (!)? Doesn't make much sense, does it?

The explanation is much simpler. 11 millimeter as measurement for the Ruger Super Warhawk (appears in some SR-novels) can be easily viewed as 11,43mm  - or .45 Long Colt - the bullet of which the .45 ACP was developed.

Additional you can see that .45 LC is only 89 Joule above the .45 ACP. That makes a 1 point increase much more logical. There is even an existing Ruger Super Blackhawk that can be purchased using .357 Magnum and .45 Long Colt. Slightly irritating would be the fact that it can be purchased using .44 Magnum as well.

But the difference between 357 Magnum / .45 LC
and .44 Magnum is still 478 / 585 Joule (much to high).
 

To determine the sequence of calibre / damagecode - list more accurate by mathematics the following was done:
The two most important statistics (calibre and EO in Joule) were multiplied to receive a single result. This is named factor in the tables.

The damagecode 7M can be understood as pistolcalibre 7,63 Mauser on one hand and as SMG-calibre
4,73 x 33 Heckler & Koch on the other hand. Last but not least because the first SR-SMG with 7M was a Heckler & Koch.
 
 

After the .50 BMG (12,7 x 99 mm) comes the calibre 12,7 x 108 Russian (E0 stats are unavailable to us). But judging by the length of the casing (about 9mm longer than the .50 BMG) and the resulting increase in gunpowder it has to be placed above the .50 BMG. The damagecode for the 12,7 x 108 mm Russian would be 15D.

The problem with this judgment in general is:
You cannot us an approach that could be called purely scientific. Instead you have to amass lots of clues and indications regarding this subject. Like the following:
The 5.56 used by the US assault rifle M16 and now sets standards for lots of other assault rifles. NATO is refitting to this calibre right now and even the Russians(*) switch to this smaller calibre.

* [The new Kalaschnikov AK-104 will be available with the new Russian standard caliber 5,45 x 39 mm not like the old version AK-47 with 7,62 x 39 - even with Kalaschnikov personally voting against this. He himself still thinks of the 7,62 as the better calibre.]

What can you do to get a picture about what could be right? You have to collect every clue you get and put them into a logical line of thought. Even with the limited number of different calibres the research in the fields of ballistics and the different calibres is still going strong since the development of the full metal jacket. That shows that there will be lots of new or advanced developments in this field. But you have to wait and see if they will push the established ones aside. It is a good possibility that the 9mm Para calibre will still be around in the year 2060 without loss of popularity. Another thing you have to keep in mind is the fact that all weapon constructors and the corporations are still producing for the international market - This means if the NATO (or whoever) uses the 5.56mm R as standard calibre for their assaultrifles that the corporations will use this calibre in their products as well => Somebody has to buy your products, right?

This and the international laws and treaties restrain the research and development of new calibres, ammunitions and the like. One of the biggest advancements was the machine-gun, later the SMG or the assaultrifle (replacing the carbine as standard infantry weapon). After this these weapons got smaller, lighter (most popular example: the UZI and later the H&K MP5). But even these features reach their limits, eventually.

Since the number of possible calibres is limited and other calibres are so close together you have to make up a sequence like we did. 7,62 x 51mm is the standard calibre for LMGs -since WW2 as a matter of fact. The next biggest calibre is 30-06, the next highest .300 Winchester Magnum and so on. You cannot look at the damagecodes on their own, you have to keep an eye on the whole picture. Before you can say that 10S = 7,62 x 51 or .308 Winchester, you will have to ask yourself what 8M (assaultrifles), 7S (LMGs) and 9S (MMGs) sould be.

The standard damagecode for LMGs is 7S. 7S is also a damagecode that is used for hunting rifles. 7,62 x 51mm is the standard calibre for LMGs and it is the most popular calibre for hunting weapons. What would be more appropriate?

7,62 x 51 = 7S or 7,62 x 51 = 10S ? If 10S = 7,62 x 51mm, what is 8M, 7S and 9S? We definitely don't want to present THE solution you have to use, nore do we want to step on somebody's toes. We just want to show that nothing is as easy as it seams. Every player can put up some statistics for their own weapons but beware if you incorporate a damagecode that relies on a specific calibre.

And by the way: Following the prologue of the adventure Elven Fire the Ranger Arms SM-3 would be a sniper rifle using the calibre .655 (about 16,64 mm), with bullets having the weight of 900 grains (58,32 Grams). A bit funny that 900 grains is the exact weight for bullets for the calibre .600 Nitro Express which is definitely smaller than .655. Bullets for the next highest calibre .700 Nitro Express have the weight of 1200 grains. This means that the weight of 900 grains for a bullet that is bigger than the normal .600 N.E. is definitely to light. Everybody may have its own thoughts about this.

But on the other hand: How do you explain that 5.56 mm R has a lower damagecode than a .45 ACP? You can't  by using only the numbers because the joule and the product of calibre and joule are higher than the numbers of the .45 ACP.

Here you got the problem that the SR-damagecodes show you the manstopping-effect of the calibre. The .45 ACP is known for its high manstopping-effect, where the 5.56 evolved out of an smaller calibre bullet used for hunting. That's a fact - even if you cannot prove it with numbers. The 5.56 as riflebullet has a longer range than the .45 ACP, but the 11,43 has a bigger manstopping-effect. That is what everybody says.

Calibres with a smaller diameter were developed for a better effect against bulletproof vests. The following idea was used: The more powder is used to propel such a small calibre the better it can penetrate such a vest (the velocity if focused on the smallest impact area. This creates a smaller tissuedamage but the resulting kinetic shock will kill the victim by crashing its blood circulation ). That's the theory.

The 5.56 cannot kill by kinetic shock neither can it penetrate bulletproof vests for sure. Other calibres like the 5,7 x 28mm by FN are much better suited to do this but only at lesser distances as the 9mm Para (- The 5,7x28 has still 232 Joule at 150 meters, this is still two thirds more than the 9mm para. At 800m there are only 44 joule left with the 5,7 x 28 but still 90 joule with the 9mm para and this would still be pretty deadly).

The problem with the idea of the 5.56 (smaller calibre being as fast as possible) is:
You will encounter the barriers of the international laws for warfare pretty fast.

The purpose of the 5.56 is to penetrate the target. This means it passes through the body of the target without causing to much tissuedamage. The resulting kinetic shock created through the hit will affect every person differently. A .45 ACP has a much higher diameter (11,43) and will result in a much greater tissuedamage. With the 5,56 having ONLY the kinetic shock to offer the  .45 ACP will give you a much bigger hole with much more massive tissuedamage and the resulting shock. Enough to make a higher damagecode look good?

Some differences will look too big to validate a increase by one point. We have to note that you have to face a problem here:
Some calibres offer nothing that could fit in between them (like the .50 A.E. and .500 Linebaugh Long) and you still have to keep the gamebalance in mind.
If you would take every exotic calibre into account there would be a list of Magnum pistols looking somewhat like that:

* Some of the statistics deviate from the other tables. This is because the stats are taken from some different sources and are only averages. Lots of the stats in the above table are so exotic they have no averages we could dig up. Instead they were only listed with a specific value. The same source states that .50 A.E. has 2528 Joule. This is higher than the average taken from another source used in the other table. The high stats of the .475 Wildy would have been compared with the lower average for the .50 A.E.! That would have resulted in an stupid lower placement of the .50 A.E. in comparison with the Wildy. That's our reason to use the higher stats in the above table.

Another possibility would be to group the calibres by the same product. That would look like this:

To set something straight: We do not write something you have to obey to. This article is something like our "Best guess" on this theme not a law. Neither something written in stone from a leader trying to convert its lost sheep back on the right way of Shadowrun. This aspect is something we do not want to make our responsibility (somebody else can take this honor and the following blame if it is wrong).