nid questions

Well with extended carpace he can get a fex a 2+ save, but it has nothing to do with toughness. If you could take biomorphs more than one time you could get a toughness of 8 by taking bonded exoskelton a ton of times if it were not against the rules to take a biomorph more than one time. But since it is against the rules you can only get your toughness up to seven. Too bad for him I guess

thanks, 2+ save is nothing to a railgun, and a T7 is no big eal for one either, im good to go!

Unless specifically stated you can never take the same upgrade twice. Furthermore no stat my EVER go higher than 10(unless its an armor value...which is for vehicles only). So even if he could take the T upgrade more than once(which he can't) he could still only get to T 10(which, again, he can't...just T7).

Unless I am misreading your post, Railgun vs. Carnifex with 2+ save is much more in the CFex's favor then a CC battle vs. a powerfist or other power weapon. The main reason being. A Railgun can only fire ONE shot per turn. If you tool the CFex to have 2+ save and 5 wounds, that will take a minimum of five turns of shooting that Railgun at it to kill it. yes it ignores its armor save, but it still has to hit and wound to be effective. Personally, the Railgun is better used as the submunition version to obliterate squads of gaunts which it does a heck of alot better.

It is, but the submunition (blast) is only available on the Hammerhead. Broadsides only get the solid shot and you can have two of them for the price of a Railgun-equiped Hammerhead.

Basically to sum up, it would be theoretically possible to increase a Carnifex to Toughness 10 if you could take their +1 toughness upgrade multiple times.

However you can't, and so it isn't.