the shape of things to come

Ultra autocannons. This is especially welcome as the RAC is particularly
prone to jams at its higher fi ring rates.
Initially produced solely by FedSuns manufacturers with the Mydron
Tornado and Mydron RC series, the FedCom Civil War saw rotary ACs quickly
proliferate to other states, particularly the Lyran Alliance and the Draconis
Combine. Fortunately, the Clans have yet to fi eld RACs of their own.
STANDARD AUTOCANNON
Introduced: Circa 2250 (Terran Alliance [AC/5]); circa 2300 (Terran Alliance
[AC/2]); 2460 (Terran Hegemony [AC/10]); 2500 (Lyran Commonwealth [AC/20])
Extinct: Circa 2820 (Clans only)
Today’s standard autocannon (identifi ed as AC in shorthand) is functionally
identical to the models used as far back as the days of the Terran
Alliance. Designed to cope with improvements in armor technologies of
the day, these weapons maintained their destructive edge through more
than 800 years of battlefi eld evolution. Even so, their time was nearing its
end when the newer Ultra and LB-X autocannon classes emerged. In fact,
among the Clans these weapons have apparently ceased to exist (their
last shots reportedly fi red in the early 3050s, when they were mounted on
machines largely regarded as refi t museum pieces). Only their relatively
inexpensive design, and the advent of specialized munitions usable by
these weapons alone, has prevented the likes of Armstrong’s J11, Mydron
models A through D, SarLon’s MaxiCannon and the Luxor Devastator-20
from becoming the next forgotten relics of history.
[Professor Habeas overlooks here certain early reports and design
specs that suggested lighter-caliber standard ACs were once intended for
ProtoMech design (perhaps as a main gun mount). However, no Proto to
date has ever carried one—likely because even the lightest such weapon
would have taken up more than half the weight of the heaviest ProtoMechs,
at huge expense in mobility and armor. Rumors suggest the Smoke Jaguars
tinkered with an old cache of standard ACs to produce LACs for this very
reason. The bottom line, however, is that Professor Habeas’ analysis was
essentially correct; by the time of the invasion, the Clans had long since
abandoned the standard AC series. By the turn of the century, most of the
remaining weapons had either been recycled or were being used to maintain
older Exodus-era low-combat units like DropShips. –EB]
ULTRA AUTOCANNON
Introduced: 2640 (Terran Hegemony [UAC/5]); circa 2820 (Clans [UAC/2,
UAC/10, UAC/20])
Extinct: 2915 (Inner Sphere)
Recovered: 3035 (Federated Suns [UAC/5]); 3057 (Free Worlds [UAC/2,
UAC/10]); 3060 (Lyran/Free Worlds [UAC/20])
The advanced Ultra autocannon system (UAC for short) was fi rst developed
at the height of the original Star League by Kawabata Weapons, Inc. of
the Terran Hegemony. Capable of higher sustained rates of fi re than standard
or LB-X autocannons, Ultra ACs could dish out twice the punishment in the
same amount of time. Unfortunately, these weapons are prone to occasional
misfi res and arming failures when pushing their maximum fi re rates—a factor
that forced many UACs into early retirement after the fall of the original Star
League. Nevertheless, the Clans (and the Inner Sphere, after encountering
AUTOCANNON
the Clans) found enough merit in Ultra ACs to expand the concept across all
the same grades as standard-model autocannons. Even though they cannot
use special munitions (their own magazines are tailored to the high-speed
firing modes, which can be dangerous or detrimental to most specialty
ammo), these weapons remain popular for attack and assault units.
Mydron, Imperator and Defi ance—the big names in heavy autocannon
technology—boast some of the most popular brand names seen today for
Inner Sphere Ultra ACs. Not surprisingly, Clan-made Ultra autocannons are
superior to those of the Inner Sphere in range, weight and size—explaining
how they, together with LB-X models, completely supplanted the
standard weapons among Clan toumans.
AUTOCANNON MUNITIONS
Having long maintained an almost romantic affi nity for the classic autocannon,
the Federated Suns—primarily through the NAIS—expended
enormous amounts of time and resources to expand the utility of these
old reliable weapons. While some eff orts wound up merely refi ning the
likes of up-and-coming autocannon models such as rotaries and Ultras,
the debut of specialized ammunitions—many fi rst test-fi red in the mid-
3050s—breathed new life into the older standard classes.
The Clans have yet to fi eld any specialized autocannon munitions in
combat, save for LB-X cluster munitions. The reasons why are unclear,
but engineers have considered the lack of standard-style ACs in the Clan
arsenal as one possible reason, coupled with the usage of diff erent alloys
and propellants than those of Spheroid autocannons that render such
specialty ammo more a liability than a boon.
Armor-Piercing Ammunition: First prototyped by the FedSuns in 3053
and reaching standard production by 3059, armor-piercing (AP) ammo uses
advanced ballistic materials and improved anti-armor warheads to deliver
a punch hard enough to damage internal systems through otherwise fresh
armor. Available solely to standard AC types, the drawback to this greater
punch is the fact that the increased weight of this ammo impairs its fi ring
accuracy and the number of rounds that can be loaded into a given bin.
Flechette Ammunition: Developed by the FedSuns in 3055 for standard
ACs, fl echette munitions deliver a shotgun-like blast of metal shards
rather than a stream of shells. Intended for use against infantry, fl echette
rounds can wipe out entire platoons of conventional troops in seconds
and can even ravage battle-armored squads, but this ammo type loses
eff ectiveness against armored targets such as vehicles and ‘Mechs.
Precision Ammunition: The most sophisticated of the advanced munitions
for standard ACs, precision ammo was developed in 3062. This ammo
type uses specialized gyrojet shells that incorporate advanced targeting
circuitry, enabling them to auto-correct their aim while in fl ight. Highly
expensive and heavy to boot, use of precision ammo—particularly in the
higher calibers—can leave an attacker empty in surprisingly short order.
LB-X Cluster Ammunition: Cluster munitions for the LB-X AC series
debuted, went extinct and were recovered at the same time as the LB-X class
of ACs themselves. These munitions may only be used by LB-X class autocannons
and do not benefi t from targeting computer assistance because of
their scattershot nature, but are eff ective against nearly all battlefi eld units,
particularly vehicles and aircraft.
Tech Base: Inner Sphere (standard, light, LB-X, rotary and Ultra ACs); Clan (LB-X and Ultra only)
Unit Restrictions: None
Game Rules: Autocannons may not be fi red if the unit is shut down or if its pilot/crew is otherwise prevented from acting, but loaded or partially
loaded AC ammo bins are always live and will explode per standard rules if critically hit during game play.
Construction Rules: OmniMechs must remove lower arm or hand actuators in any Arm location selected to carry an autocannon. Of the autocannons
available, only the Standard AC/20, LB 20-X AC and Ultra AC/20 may be split among two adjacent locations (such as the Left Arm and Left Torso)
on BattleMechs and IndustrialMechs. Weapons so divided must take the most restrictive fi ring arc of the two locations. Non-’Mech units may not
divide a single weapon among multiple locations.
Only standard and light autocannons may make use of specialized ammo beyond LB-X cluster munitions. LB-X cluster munitions may be used only
by LB-X AC types, which may also use standard AC ammo (but no other special ammo types). Ultra and rotary ACs may not use specialized ammo.
Table Reference: Weapons and Equipment (Inner Sphere and Clan, pp. 341–343) Game Rules: Total Warfare, p. 98
i