Gunner build?

Starting a new run today and want to try out gunners, I’ve always found them a bit lacklustre so want the community’s advice on building them effectively? As far as I can tell the required perks are. Quick hands, fast adaptation, crossbow mastery, fortified mind and fearsome. Likely additions of nimble, overwhelm and killing frenzy.

I’ve seen a lot of builds go for berserk but I don’t really understand why - you can kill reload and shoot again with berserk but once that’s done once you can’t do it again as reload, kill, then insufficient AP to reload again even with berserk. At best you could quick hands into a jav?

Anyway would appreciate some fun builds thatve worked well for people and advice on how to use them :)