None of the ammo types given in the book (starting to page 192) quite match the Autocannon. It's not a Vehicle-class cannon, so it's not Artillery. Bullets begins with "Hard rounds are common…" and the Autocannon is said to use solid shells, but it's not listed as a weapon that uses Bullets. Should it have it's own entry?

If they do have their own entry, what should the Availability be? Bullets are Plentiful while Bolt rounds are Rare and Artillery is Very Rare. I'm thinking of going with Common or Average, but I was wondering if anyone else had any insight on this.

an autocannon round is basically a bolt round without the explosive core.

technically its uses normal bullets but of a higher caliber
comparable to a bushmaster autocannon in reallife which uses 25mm bullets

in no way does it use bolts, bolts have a primary charge like bullets but thats way smaller just to exit the barrel when a rocket engine kicks in, thats why the are so much more hard to produce and more expensive

I'd leave it at plentiful or at most common. It's an extremely common crew served support weapon. It's very similar to modern squad support weapons which the military has crates and crates of ammunition for. It's very different from the rarity of bolt or plasma/melta ammo.

Nightcloak said:

Correct, they are the same caliber as a bolt round and similer in most ways (adamantium tip, same caliber, etc) however it does not contain the explosive charge though older models used to use explosive rounds. So they are like a bolt round but not as powerful.

Droma said:

Oddly enough, the autocannon itself has Very Rare Availability, but this is on the same scale that gives the Heavy Stubber a Rare Availability.

Robomummy said:

Um…

The Autocannon hits much harder than the heavy bolter at considerably longer ranges.

It does so as a (rather big) conventional firearm rather than as a multi-stage mini-rocket and it does it's damage with a solid round rather than an explosive charge. I'm not really sure how these weapons are similar beyond the extrememly general description of being non-energy heavy weapons.

HappyDaze said:

Autocannons are similar in concept to twentieth century tank guns. ^[1] They are rapid-firing weapons able to use a wide variety of ammunition, from mass-reactive explosive ^[1] to solid shells. ^{( http://wh40k.lexicanum.com/wiki/Autocannon )}

HappyDaze said:

I realize i never answered your question, sorry about that. I would say depending on how well supplied the regiment is it would be fairly common. Autocannons are usually commonly seen in most regiments so it stands to reason that there should be plentiful ammo for it. Other than a well supplied regiment It might be rare since it is such a large caliber and you probably not see alot of heretics carrying them (unless the heretics are well supplied as well, which is likely if they are PDF or severan dominate).

As far as I am aware the knowledge on how to produce the mass reactive shells has been lost.

Of course this is a background explanation to explain the change from a blast template weapon (1st edition 40k) to a rapid fire solid shot weapon (2nd edition onwards). In 1st edition Autocannons where just tank guns, and they were called autocannons purely because the shells were automatically loaded. Second edition onwards (I think maybe even with the battle manual for 1st edition) they became more like the general real-life understanding of autocannon (ie, and automatic weapon of a greater calibre than a heavy machine gun).

Robomummy said:

indeed they CAN shot special rounds which are covered under the special ammunitons and cost, depending on type, more
the standard round is a normal solid projectile round similar to a FMJ round and those are wayyyy more easier to produce and need way less technological knowhow too