Whats the deat with combi weapons, thunder hammers, and multimeltas?

sorry if this is answered somewhere else.

There's a thread in the Q&A section. (link provided below.)

Unification & Heresy Weapons

But off the top of my head,
Combi weapons were about.
Thunder hammers & Multimeltas i'm not too sure on, sorry.

Hope this helps. :)

Thunder hammers, I believe did exist. Eidolon carries one, and there is mention in Flight Of The Eisenstein on Page 195 of two Death Guard from the Command Squad of the 2nd Great Company carrying "heavy combat hammers".

Of course, how stupid of me.
(More "Hail Warmasters!" for me then. :D)

You're doing well with those...

Thunder hammers per se certainly were post-heresy at least up until 3rd ed. – Chaos Terminators had to make do with their forerunners, power mauls.

Of course, that doesn't prevent you using 'power hammers' or similar, but if you wanted to be conservative in your interpretation, count them simply as power weapons rather than thunder hammers.

With all of these sorts of questions, I always err on the side of caution – while there probably were Thunder Hammers or plasma cannons or whatever, they're not particularly associated with the pre-heresy era. By including them (or things that look like thunder hammers etc), you dilute the pre-heresy appearance and impact.

Basically, my approach is: if in doubt, leave it out.
I actually find these sorts of restrictions improve the feel of my army, as it forces me to try new things and approaches.

As a final thought, you should always do what you like – after all, screw the rules and do what's cool: there's always an explanation! :)

I'm not sure if they are thunder hammers, but Perturabo and his first captain both carry hammers of some kind.

I was looking through the horus heresy collected visions book, and came across 2 plasma cannons that marines were holding. I also saw a squad of longfangs with assault cannons.

If you count the new Horus Heresy novels as Fluff (Meoww * Snap*) :D
Xayver Jubal's Helbore Squad of the Luna Wolves used a Plasma Cannon in Horus Rising (Pg 20).

Assault Cannons however were still in the prototype stage during the Crusade.
Some of the Artwork has to be taken with a grain of salt unfortunately. <_<

I'd say that as all plasma weaponry is "ancient and revered" in 40k then some cannons would definitely be around during the heresy.Whenever i'm in doubt i say its experimental weaponry,but then again thats the joy of being daddy's favoured kids(pun intented :D )...

I guess we can take the HH books as cannon,since the whole story of inter-Legion cleansing and Angron getting down on Istvaan III from GiF was included in the latest chaos codex.