My GM has made it clear that i won't be able to get a force weapon of my own. I will be able to borrow it a bit like in Deathwatch when you can ask for specific items depending on the mission.
I have a pretty strong psyker character due to high rolls on strength, advances, and the brute mutation, i have SB 5 and a light power armor (+10), and crushing blow to complete the picture.
The first thing that came to my mind was to get a powerfist since the damage would be pretty nasty: 2d10 + 14 with a big penetration value. My GM wasn't really happy with this idea either and fluffwise that could be a bit strange to see a psyker wearing a powerfist.
I have thought about a powersword, which ensures good damage output, energy field, and the balanced attribute, but our guardsman already have one and i want to have something different. I have thought about using my high str value to weild a big powersword but the stats from the two handed powersword is not really Worth it. Basically, the powersword makes 1 d 10 + 5 and is balanced, while the two handed powersword (IH) is 1 d 10 + 6 meaning you lose the balanced quality for a low +1 damage. Plus, i want to be able to hold a gun in my secondhand. I would consider wielding a weapon two handed if the damage is really significant, but i have found that aside from eviscerator and thunderhammer (eviscerator is more a priest thing and i won't be able to have a thunderhammer if my gm doesn't allow me to have a powerfist), they have not enough punch compared to being able to hit and fire with a gun.
I was wondering if i could instead get a best quality chainaxe ( 1 d 10 + 5 pen 2 tearing + 10 WS), which would mean doing 1 d 10 + 13 damage pen 2 with tearing quality and a nice bonus to hit.
I am searching for something obviously big, since my char has SB 52 and T 50. The issue is that aside from the chainaxe i can't find a big weapon thats really Worth it. The chainaxe sacrifices the balanced quality (but isn't imbalanced in RAW) for 2 points of damage, which is fine, otherwise, the other big weapons aren't really Worth it.
We have thought about the possibility of wielding a great weapon in one hand but even a best quality mono great weapon is close to the chainaxe in terms of damage, but is unwieldy.