so tech priests get mechanis implants and mechandrite use for free at start, bitchin'. then two implants of choice (no limiting factors really?) also pretty rockin' from a player P.O.V.
so ill just take a ballistic mechandrite and the weapon interface MiU set my self up for two weapon weilder ballistic and have FOUR guns! wait, what? yeah dude FOUR GUNS at full auto all the time! uh…. no…..

not actually the conversation but that's a basic break down, so how does it actually work? im pretty much convinced its he can fire a tank while driving with no penalty or, can fire the pistol weapon in his mechandrite on his turn with no penalty in addition to his reaction shot.

also seriously the lack of limits on starting implants is frightening. it might just be the horrors of deathwatch kicking in but unnatural statistic for free at char gen is mind ****.

No matter how many arms or arm-like apandages you have you may only ever perform one action with the attack subtype per round.
So if you have two weapon wielder and four arms you may fire any two of those four weapons using one attack action.

Now attacking with a Balistic Mechadendrite's a different thing I believe since its a reaction. Now I'm not quite sure about the RAW there but I believe that this allows you a second attack per round (but not on your turn since reactions are always taken on the enemies turn).

I know this isn't gonna make me any friends, but I gotta say, I've always felt the ballistic mechadendrite is a bit meh. People always seem to bee all over it, but in the end its just a compact pistol weapon, oh boy.

With those free cybernetics I'd go for a good quality Cerebral implant, Autosanguine implants, and a medicae mechadendrite. Get the Weapon Tech talent as early as possible.

weapon interface MiU allows a shot, regardless of what other actions you are taking for free..
its often shouler mounted is all they really give for restriction which is vauge at best, at worst negligent of potential abuse.

what im looking for really is a clarification as to how the hell does the the MiU weapon interface work? does it require a mechandrite? the way it reads it doesnt but it doesnt explain what implant is needed for the shoulder mount.

MIU - Allows you to plug into "MIU enabled" devices. Provides a +10 to pretty much any test involved when using them. Note that what is "MIU enabled" is a broad notion, and highly up to GM interpretation.

MIU Weapon Interface - Allows for a connected weapon to be fired as a free action. I'd allow this with a mechadendrite, sure (its not like a "free" shot from a compact weapon is going to break a campaign). As far as other uses, note that the cybernetic itself doesn't provide the weapon or the shoulder turret mount. As far as firing from a vehicle, sure, if the weapon is enabled (very well could be). Note that it does not negate situational penalties from using the weapon, e.g. the -20 from firing while moving full out in a vehicle.

the player in question is at the moment hunting for flaws in the system because thats what he does, his new idea is weapon MiU + optical mechandrite + medical mechandrite+ sniper rifle + meidcade skill = tech preist sniper and combat medic at the same time.

what implant would be needed to mount a weapon on the player other than a ballistic mechandrite?

Well the ballistic mechadendrite can't handle basic weapons, so that right there stops part of that idea. As far a shoulder mounting for basic weapons… I dunno, I'd have to read the new rules for integrated weapons in Lathe Worlds for Dark Heresy, that might have part of what you want.

Still, I would say its not as simple as get a sniper rifle, and an few other attachments. It would take a GM ruling in the affirmative to say the Weapon MIU works with a stock sniper rifle.

Unlike the "extra arms" attribute and all its friends, additional ranged weapons do not grant additional attacks. If I have Eight arms with a blade [or not] in each, I can get 2 [normal two-weapon-wielder] attacks, plus four [and these could be swifts too], all as part of the same action. We're looking at a potential maximum number of hits equal to 6*WS.

If instead all those extra arms were filled with pistols, you get… your normal two-weapon-wielder attacks as one action. And as a reaction you're allowed to use a mechadendrite.

That's it. A Weapon MIU doesn't even technically count as a one-handed weapon, though if you're already sporting weapon-bracing or slayer arms, it should be a very "yeah sure whatever" case of asking your GM. One game I was a part of, I was allowed to use two two-handed weapons: One on the MIU, the other in-hand. Of course, given what the melee tank was pulling off [a WS70+ Sb6 guy with x3 unnatural strength when using power-fists] it was kinda needed.

If you want to mount a weapon on a character, you have the following options other than the dendrite, which is kind of a seperate affair:

-Weapon MIU

-Weapon Bracing [perfectly compatible with the actual MIU, but a different implant of its own]

-Armour upgrades [Concealed Weapon and Tool Mount]

-Slayer Limb Mutation [marginally quite heretical, very slightly blatantly obvious]

-There's also Recoil Gloves, which let you use a basic weapon one-handed with no penalties, though its not mounted

-And failing that there's also Carbine models, which have a -10 instead of -20 penalty for using one-handed.

All of these save the MIU allow you to use the weapon one-handed, meaning you could technically be dual-wielding them.

Finally there's one more thing the character can do, which allows for extra actions up to a point: Get himself a minion, or a servitor or servo-skull or whatever you wanna call it. Or a vehicle. Even a simple bike could mount a heavy weapon, which you can then MIU uplink with.