In warhammer 40k the Astra Militarum and planetary defence forces of the imperium of man are known to make use of Auto-Weapons which from their description in the wiki http://warhammer40k.wikia.com/wiki/Auto_Weapons seem to differ little from modern-day weaponry. That being said it has been thirty thousand years and one would expect some-kind of improvements compared to the weaponry of today, is there anything in the imperial guard books or other material that would suggest this?

I ask because it would seem to put an end to the ongoing debate "would modern weapons be effective in 40K" if modern weapons are being used in the universe.

4 Answers 4


Yes modern weaponry is similar to some 40K weaponry and probably would still be useful but mostly against other humans that have similar weaponry.

Weaponry that we recognize today like shotguns, machine guns and other types of weapons still exist and are used in 30K/40K. They have the benefit of being relatively easy to produce without needing a lot of high tech knowledge, so low tech worlds in the Imperium are able to produce those themselves.

So no, they do not differ much in operation. However how powerful they are will differ a lot based on what materials used and the caliber of the gun.

Comparing a current day M4 with a Agripinaa pattern type II Autogun, which is described as having 8.25 as its caliber (which is significantly higher than the M4's 5.56), with its rate of fire and muzzle velocity not being impaired by the larger caliber with a rate of fire of 625 rpm and a muzzle velocity of 825 m/sec to the M4's 700–950 rpm and muzzle velocity of 910 m/sec.

So comparing two fairly common weapons of a similar type you can see: whilst very similar, the 40K rifle is more powerful due to its higher caliber. So I think it's safe to say that they are overall just stronger than current day rifles when compared. But I do think our weaponry could still be of use within some types of warfare in the 40K universe. Especially among other humans like in Hive cities.

As to how they are used and how effective auto rifles are.

Against other humans with similar level of tech they would still be useful. though they will be useless against anything among the line of Astartes or most Xenos races.

The technology, however, is also used by more advanced weaponry that is used by Astartes and Adeptus mechanicus. Astartes terminators also use auto rifle technology in their Assault cannons which would be similar to how a modern day minigun would work. It allows for more damage than similar caliber weapons due to its very high rate of fire.

However I think it's less about the workings of the weaponry but more about the ammunition that is used.

The technology of how Auto weapons are used is simple and effective and will work regardless of time period. What's more important is what type of ammunition is used.

Astartes Boltguns also work in a simple way just like auto weaponry, but are immensely powerful due to the power of the ammunition that is used. It is really big in size and detonates after impact, so they are basically mini rockets, but the weaponry that is used to fire them is pretty simple in inner workings.

Standard bolts comprise the following components: outer casing, propellant base, main charge, mass reactive detonator cap, depleted deuterium core, diamantine tip. The caliber of the standard round is .75 and it possesses a super-dense metallic core.

A sub-human race known as the Interex were encountered by the Luna Wolves during the great crusade. They were noted to heavily use Bows as a main part of their armament.

Horus Rising by Dan Abnett

The soldiers – variously gleves or sagittars, Loken learned – were almost as tall as the Astartes, but with their far more slender build and more closely fitted armour, they seemed slight compared to the Imperial giants. Abaddon, at the first meeting, muttered that he doubted their fancy armour would stand even a slap. Their weapons caused more remarks. Most of the soldiers had swords sheathed across their backs. Some, the gleves, carried long-bladed metal spears with heavy ball counterweights on the base ends. The others, the sagittars, carried recurve bows wrought from some dark metal. The sagittars had sheaves of long, flightless darts laced to their right thighs.

Which the astartes were mocking them for:

‘Bows?’ Torgaddon whispered. ‘Really? They stun us with the power and scale of their vessels, then come aboard carrying bows?’ ‘They’re probably ceremonial,’ Aximand murmured.

However at a later part in the book it shows them use the weaponry. And it shows them to be superior weapons that easily best the Astartes Power armor used by the Luna Wolves

More flashes, like laser fire. Projectiles, moving so fast they were just lines of light, zipped down the colonnade, faster than Loken could track. Oltrentz dropped onto his knees with a heavy clang, transfixed by two flightless arrows that had cut clean through his Mark IV plate. Clean through. Loken could still remember Torgaddon’s amusement and Aximand’s assurance… They’re probably ceremonial.

I think this is a really good example as to Ancient weaponry can still be really useful with the right ammunition.

  • 3
    I read somewhere that during and/or after the 2 word wars, the caliber for infantry weapons shrank a lot. It was showing that the smaller calibers are absolutely sufficient to stop humans, but the they also mean less weight, which means a more mobile soldier, which means a more efficient soldier. By the very same (realistic) logic, you'd of course have to resort to bigger calibers to fight against guys in HUGE ASS INCH THICK FUTURE STEEL PAULDRONS.
    – R. Schmitz
    Commented Aug 8, 2018 at 9:24
  • @R.Schmitz smaller calibre also means more likely to stop and wound than kill outright, tying resources up to care for the injured combatant. Commented Aug 8, 2018 at 10:24
  • I've read that the universal loading chamber of the Autogun accepts a whole range of calibers, which (as of my knowledge) no current age weapon does. Together with the robustness to function through a dropship-assault in a swamp and through the desert, most current age weaponry would just cease to function half way through
    – Falco
    Commented Aug 8, 2018 at 11:58

I don't think they do differ much from conventional weapons in terms of mechanics. Auto weapons are just slug throwers. They don't have the aiming system of bolters (or more precisely, bolt shells) and they don't have any performance advantages over lasguns.

The performance difference might just be in ammo payload. A 40k autogun shell might simply be many times more powerful than a similar sized shell from this century.

The real advantage of auto weapons is probably not performance related anyway but rather logistical: they're cheap to make and supply in the 41st millennium. Even hive-gangers can do it. That might be the most remarkable difference from contemporary weaponry. Producing and servicing autoguns may be the 40k equivalent of sharpening a pencil.

  • I don't have references to hand, but it's actually explicit in the setting that the logistical advantage goes to *las-*weaponry, not autoguns. Stubbers are technologically simpler so easier to produce but lasgun power cells are ubiquitous, almost universally interchangeable, and easily rechargeable so you only have to worry about supplying power - in fact, a standard lasgun cell will recharge over a day left in sunlight or even (in dire circumstances, because it can damage the cell) put directly into a fire.
    – Carcer
    Commented Aug 7, 2018 at 21:14
  • It has been mentioned somewhere that autoguns are better solution when fighting Orks, that are much more resistant to the piercing damage from laser weapons. Orks also more "respect" the noise the autoguns make (so it is easier to break their morale and rout them)
    – Yasskier
    Commented Aug 7, 2018 at 22:52
  • I don't think it's ever been mentioned explicitly, but energy weapons generally are less effective against daemons, I'd expect autoguns to be a better option against lesser daemons than a lasgun. Funnily enough, this is borne out by the standard rule of thumb that a faction always carries the weapons best suited to fighting itself..Chaos Cultists generally carry autoguns. Commented Aug 8, 2018 at 9:19

According to the Related Wikis, Autoguns in 40k are pretty comparable to modern ones, 8.25mm ammunition, similar physical size, similar ammunition and rough design.

Practically they're a little heavier hitting than average for modern weaponry but nothing exceptional.

They're noted to be particularly robust however, generally built with the mindset of the AK-47, meant to handle rough treatment and less-than-precise manufacturing tolerances on the ammunition.

Most are essentially a heavier-caliber AK.

Fair to say that a modern assault rifle in 40k would be considerably more precisely manufactured, slightly lighter on stopping-power, but much more accurate and reliable than an autogun.

So in real terms, yes, absolutely modern weaponry would be effective in 40k, in fluff terms Small-Arms plink off a space marine like a light rain, but 40k as a whole has an emphasis on armour over weaponry compared to the modern day which is the other way around.


Heck no. Modern weaponry is designed to injure, not kill. And injuring an opponent doesn't really work in 40k (Ex. Orks, 'Nids, 'Crons, Chaos, Kriegsmen, Space Marines)

  • Hi, welcome to SF&F. This is extremely brief; could you flesh this out into a longer answer? Possibly by comparing specific weapon classes (small arms, squad weapons, etc.) and targets (modern battledress vs. WH40k armour). Please read How to Answer.
    – DavidW
    Commented Mar 8, 2021 at 23:34

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