So I'm just wondering what others take on these sorts of guns is. The description says the weapon cannot be further modified. I take this to mean you cannot add any modifications but accessories are still possible (it has it's barrel, top and under mount still available for say a gas vent system, fore-grip and scope for example). Now if you wanted these accessories to also gain the MAD bonus the gun itself does, they must also be MAD modified (ceramic components) and are thus quite expensive.
Do other GMs see it as the weapon cannot be modified at all (no accessories or mods) or just no further mods but accessories are still possible? I remember something similar with the Ingram White Knight with the wording being it cannot be further upgraded and some confusion as to whether that referred to the gas vent system or the whole gun.
So do you feel allowing accessories for these weapons (HK Urban Combat and Urban Fighter) to be too unbalancing? I mean you could modify any weapon in the game to use level 3 ceramic components to achieve the same result as these guns taking 1 mod slot and increasing the price by 6 times (of course every other mod also gets increased by this amount too ).

I'd say you can't mod, for example, the Urban Combat. Most of its mounts are already taken, and it's fluffed such that it seems this is what they were going for. YMMV.

You can add accessories to the cannot be modified weapons, however, keep in mind that a silencer/suppressor and gas vent are incompatible. And while you can house rule any accessory can be made from ceramic/plasteel components for the cost multiplier from the weapon mods table, it is not RAW, and may not work with some GMs.

Well since I am the GM that won't really be the problem. I'm just looking to see what other GMs have done with these sort of weapons.

It really depends on the weapon. Some cannot take certain types of mods, and others cannot take certain types of accessoriesz(underbarrel on the praetor).

In practice, its too much of a headache to keep track of which-weapon-can't-take-what, so I don't think many people bother.

I dunno, in practice people know exactly what their guns can and can't do.

Yeah, but when's the last time you saw someone actually -use- an urban combat in gameplay?

Or even carry.

Because it's not MADs you need to worry about anymore, but cyberscanners and chemsniffers.

The Urban Fighter and Urban Combat both used sealed ammo clips so chem sniffers aren't a problem.

Yeah but a cyber scanner will find it no matter what.
And most secure building probaply have those at the door.

Really the whole ceramic weapons think doesn't make any sense, it's completdly useless to make your gun inviciple to MAD-scanners.