GrandMaster BT
Personally Im going to be sculpting mine out of greenstuff
Well, GW put us in a bind with the ACs' design.
1) Just tell your opponent what he is really equipped with. Most people do not mind that.
2) I have browsed the GW online store for powerfist and they are always on the left hand, so that makes the pistol on our AC left hand out of question and we now have to replace both weapons.
3) I happen to have a box of troops CSM and it has plenty of right handed pistols in it. It also has a sprue for the AC's weaponry which inlcudes a Left handed powerfist. This is the way to go.
4) You do not need to replace the right handed sword on the AC if you do not want to as you should be using a psychic power in the shooting phase anyway. This includes GoC, BoC, WoC, and Doombolt which are our common psychic spells used which are all used in the shooting phase. The only time you would actually benefit from having a pistol in the right hand would be if you ever want to use Inferno bolts.
5) Another option for powerfists is to buy a Space Marine CC terminator sprue as it has about 4 powerfists and 4 chainfists but that will cost you more $$, but if you think you will ever use the rest of the bits on that sprue then go for that one, just a little bit of filing of the imperiums insignia and there you have it! Black templars also has these powerfists.
I hope that helps!
