Stubbers and Autoguns - more Dakka for your money!

Many non military personnel often ask about the difference between the Stubber and ‘Auto’ family of weapons. To the outside observer they often fulfil similar roles, both being projectile based weapons falling into categories between hand guns and heavy machine guns (and above for auto-weapons). Both have weapons capable of sustained automatic fire, use a variety of rounds (including some with explosive warheads) and can be found in common service across thousands of Imperial Guard regiments.

Outwardly both weapon families function in a similar way, they both use a propellant to fire a bullet (often called a slug or stub) at the enemy at high velocity, using the rounds kinetic energy (and sometimes warhead) to cause damage. It is only when you examine the internal workings of the weapons do the differences become clear.

Before we examine the differences we should look at the similarities. Technically speaking Auto-weapons are a sub-family of the Stub weapons group as they too, generally, fire ‘stubs’, simple bullets without a warhead. That being said some of the larger Heavy Stubbers have been observed to fire rounds with warheads making them, technically, not a Stub weapon. Ammunition is often interchangeable between the two weapon types, with rounds from a stub gun working in an Autopistol and vice-versa.

If we look at the different weapons categories commonly found in the two families we see remarkable overlap between them.

Handguns: The smallest hand guns tend to be the Stubguns, available in a ‘revolver’ format or in a semi automatic style. Some Stubguns have even been converted to fully automatic fire. Auto Pistols on the other hand are substantially larger, though can be fired from one hand by a strong and well trained user. Auto Pistols universally have a fully automatic fire mode.

Sub Machines Gun and Assault Carbines: The formal difference between these two weapons systems has blurred due to classification differences by the many manufacturers across the Imperium. Suffice to say that both offer high rates of fire in a compact, two handed package. In general the Assault Carbines tend to use rifle rounds and the sub-machine guns tend to use pistol rounds but in terms of use they both fulfil similar roles, providing rapid fire for short range engagements (though carbines are of use in mid range engagements as well). Both the Stub and Auto families are well represented in these weapon packages with comparable functionality between the two systems.

Rifles, Assault Rifles and Battle Rifles: In the pure rifle (weapons designed for accurate single shot placement at medium to long ranges) category there are only weapons from the ‘stub’ family though both weapon systems are used in the Assault/Battle rifle group offering both automatic and burst fire capabilities over a good range.

Squad Automatic Weapons/Light Machines Guns, Medium and Heavy Machine Guns: Over a variety of calibres all categories can be found in both Auto and Stub configurations though the Heavy Stubber is one of the most common Medium and Heavy machine guns in the Imperial Armoury there are some ‘Light Auto Cannons’ in some regiments. It may be useful to note the difference between the three categories listed above. SAWs/light machine guns are designed to provide sustained automatic fire on the move for a unit and are often modified assault rifles with a higher rate of fire and larger ammunition capacity. A SAW is designed to be operated by a single user though in reality the extra weight of ammunition is often shared with the rest of the unit. Medium Machine Guns are specialist weapons firing a rifle cartridge with a greatly increased rate of fire and ammunition capacity. Although some users are able to fire medium machine guns on the move they normally require the use of a brace or a bipod. Medium machine guns are normally served by a crew of two, one firer and one loader who carries additional ammunition of the weapons mount when on the move. Heavy machine guns fire larger rounds than regular rifles and require a specific mount to use, in some cases a tripod, in other a special weapon carridge. Lighter systems may be man packed by a two man crew but many systems require 3 or more operators. The heaviest ‘heavy machine guns’ actually require assembly after transportation with 1 crew member carrying the tripod, one carrying the main part of the weapon, the third the weapons barrel and the forth the ammunition.

Cannon: Above a certain size Stub weapons cease to be a viable option due to problems feeding ammo. This limit is generally seen as 20mm ammunition, anything larger than this is only seen in the Autocannon classification. An Autocannon is a high calibre weapon capable of sustained automatic fire with a fire rate of greater than three rounds per second. Autocannon are capable of firing a variety of special purpose rounds from depleted uranium anti tank rounds to high explosive anti personnel shells, proximity anti aircraft munitions and so on. Autocannons have calibres from 15mm to 150mm, anything larger and the automatic weapon feeds can not move the shells fast enough.

The principal functional difference between the Stub and Auto family of weapons comes down to the way fresh rounds are chambered for each shot. All Auto weapons (from the Slipstream 5mm auto pistol to the Devastation class 150mm Auto Cannon) use a motorized feed system to bring a fresh round from the ammunition supply to the breech for each shot. Stub weapons either have to be manually reloaded or utilise gas pressure or recoil from the previous shot. The same technology that is used to feed Bolters is used in the Autoweapon family allowing for a reliable high rate of fire from such a compact weapon system.

Assault Cannons.
These potent weapon systems were developed from low calibre autocannons, substituting the power of larger shells for an awe inspiring rate of fire. Assault Cannons are only available in a few calibres with Terminators normally carry the lightest, the 10mm version, and tanks and dreadnoughts using 15mm or in some cases 20mm shells. With cyclic rates of fire up to 7200 rounds per minute (120 rounds per second) the assault cannon is one of the most psychologically effective weapons available. Although the individual rounds are not as powerful as larger autocannon rounds, the high rate of fire allows it to engage targets larger than its calibre suggests. Some myths have surfaced in the Imperial Guard regiments over the power of this weapons with some ill informed fans claiming it is potent enough to engage Titans. The Assault Cannons high rate of fire means that it suffers vast amounts of wear and tear. The weapon is considered at least partially disposable. Tank mounted models generally have new barrels and bearings replaced for each battle. Terminator mounted models come in a single disposable package. As Terminators are unable to reload their weapons during battle the entire weapon is sealed. When the unit runs out of ammo or jams and can not be cleared by the autofeed system (which is too common for many users liking) the entire weapon system is detatched from the armour and abandoned.

As a side note I was proud to witness first hand the testing of a new weapon system, a quad mounting of the Devastation class on power assisted universal weapon platform. The system features four 150mm Autocannon and is designed as both a heavy anti-tank/titan weapon and as a defence turret installation for the Ramilies class Starfort. The weapon system had 4 weapons slaved to fire in sequence, each one fed from a 12 round clip (each weighing several tonnes). The weapons are cycled using an 24 litre multifuel engine, the same model used in many Leman Russ battletanks. This powerful motor allows the weapon to fully expend its ammunition in 4 seconds giving a cyclic rate of fire of 720 rounds per minute. The weapon has a slow reloading cycle, the ammunition clips are too heavy for regular Sentinel lift units and need a larger crane or lifter, but this was not seen as a problem as there are few targets that could withstand 48 150mm high velocity shells.