Bullpup's been around since 1901. The inspiration for the ACR (at least regarding the artwork), the EM2, was around in the early 50's. Many of the 'short' assault rifles are not bullpup, also.
I know they are not the same. The Walther PPK has got very different performance to the .45 ACP. A Bergman MP-18 is very different to a P90. RPGs do not model this well, Traveller included. It's only ever a very rough approximation. [edit] Semi-auto SMGs
are called carbines, btw.
http://en.wikipedia.org/wiki/Carbine#Other_carbines
And I don't think it's 'frothing fans' - it's more some people pointing out that the SMG class
has been covered in the rules, when some folk thought it hadn't. Personally, I'd have included the SMG as a low tech auto-carbine, just to keep the peace, if anything. But the weapon
effectively exists now within the rules. The exact terminology is, of course, up to the ref.
Sorry, but I don't think that the evidence supports this assertion.
Carbines--whether auto or semiauto--have historically been considered a different class of weapon than SMGs (anonymously sourced Wikipedia articles notwithstanding).
In general, carbines fall between rifles and SMGs in muzzle velocity, muzzle energy and (particularly) barrel length. Consider some TL5 representative samples:
Rifle: M1 Garand, firing the .30-06 (7.62x63mm) round, 3894J muzzle energy, 24" barrel
Carbine: M1/M2 Carbine, firing the .30 Carbine (7.62x33mm) round, 1190J muzzle energy, 18" barrel
SMG: M3 "Grease Gun", firing the .45 ACP pistol round, 706J muzzle energy, 8" barrel; Thompson SMG, firing the .45ACP round, 10.5" barrel (some unsuccessful variants had longer barrels and different ammo).
Pistol: Colt M1911, firing the .45 ACP pistol round, 386-600J? muzzle energy, 3.5-5" barrel.
Many carbines fire pistol rounds, instead of special carbine rounds. Even though the ammunition is the same, such carbines generate significantly more muzzle energy than pistols or SMGs because of their significanly longer barrels. A TL5 example is the Marlin Model 1894 lever action carbine, which is chambered for .357 magnum, .44 magnum or .38 special pistol rounds. The Hi-Point 995 carbine (9x19mm), with 16.5" or 17.5" barrel (which even uses the same magazines as the Hi-Point 9mm pistol) is a TL7 example. The Berretta Cx4 Storm, with a 16.6" barrel is another example, using 9mm, .40 S&W or .45 ACP ammo and Baretta pistol magazines.
The development of assault rifles has caused some overlap with carbines. Assault rifles typically have 20" barrels, which makes them longer than carbines, but shorter than rifles. However, many assault rifles have 16" variants, which are also called "carbines". For instance, the M4 carbine, which is an M-16 with a 16.5" barrel.
However, assault rifles and their short barreled variants have significantly higher muzzle energy than other carbines -- ~1900J compared with ~1200J or less.
Modern submachineguns have *significantly* shorter barrels than carbines and usually fire pistol ammo (the 9x19mm round is popular). Representative weapons are the UZI (10.2" barrel) and the HK MP5 (5.5-8.9" barrel). Some new SMGs fire proprietary ammo, but the performance of the ammo is comparable to pistol ammo. Example--the FN P90, which fires a new 5.7x28mm bullet and has a 10.1" barrel (393-538J muzzle energy). Compare this to the M4 carbine, which fires a 5.56x45mm cartridge (with ~1900J muzzle energy) and has a 16" barrel.
Bottom line -- there are at least two characteristics that distinguish carbines from rifles and SMGs--barrel length and muzzle energy. Barrel length is the most obvious:
Rifles: 24"+
Assault Rifles: 20"
Carbines: ~14-18"
SMGs: 5"-10.5"
Pistols: 2-5.5"
Extrapolating from these characteristics and representative weapons, a carbine will have significantly greater effective range (~200m vs. ~50m for the SMG) than a SMG and significanrly higher stopping power. It will be heavier and less handy and will have slightly more recoil, unless firing pistol class ammo.
So I'm sorry, a "carbine" is not the same as a "submachinegun" and is not roughly comparable in capability. Yet another example of a purported game designer not bothering to educate himself on the subject, IMHO. MGT fans would do well to stop defending such oversights and simply ask that the designer do his job.