In my next campaign I'm going to do the fighter, battlemaster,

Assuming you don't run out of ammunition it's one of the best damage options in the system, but you're still not as good as a well played caster like a Wizard, so.

>>51001694
1. Hard to say. Those would be really useful. Maybe Lucky, to reroll attacks. It's sort of all-purpose functional.

2. The build is fine, but not particularly more powerful than using a longbow. You have a slightly higher damage output, but with the longbow you'd have an extra feat to dump on something else, because crossbow mastery would be superfluous.
I doubt you'll be unbalancing anything.

>>51001715
At what level would a well played caster surpass me?

>>51001725
If I were to use a longbow, and considering I would have many feats, what are all of them that you would recommend?

>>51001725
I'd say it'd be a bit more than slightly higher if he dual wields hand crossbows.

>>51001769
I was under the impression that duel wielding hand crossbows was against the rules. Is this not the case?

>>51001806
The dual wielding rules in general in 5e specify throwing weapons or melee. However, Crossbow Expert specifically says "When you use the Attack action and attack with a one-handed weapon, you can use a bonus action to attack with a loaded hand crossbow you are holding.", as well as "You ignore the loading quality of crossbows with which you are proficient.".

Dual wielding hand crossbows should be fine by RAW, whether or not a GM asks how you're loading both of them with both of your hands full. Arguably due to the wording you could simply make a bonus action attack with the same hand crossbow that you used to make the attack that would qualify the bonus action to begin with instead of dual wielding.

>>51001769
Technically, the RAW rules don't allow for dual-wielding ranged weapons. You can duel wield light melee, or thrown, but not ranged.

Disregarding that, you'd probably be doing somewhat better damage, but you'd also need to pick up the "Two Weapon fighting master" feat, so you could still use your bonus action for something.
With the Extra attacks, the two options will probably start to even out, but at low lvl, the dual wielding will probably dominate.

At lvl 1 a dual-wielder would do
>2d6+4 (with 19 dex) -> Av. 11 dam
Heavy crossbow
>1d10+4 -> Av. 9.5 dam
(Provided you hit stuff) - but the heavy crossbow guy would still have his bon. act.

At lvl 5. dual wielder does:
3d6+8 (if dex is still 19) -> Av. 18.5 dam
Heavy crossbow does:
2d10+8 -> Av. 19 dam

>>51001863
With regard to dual-wielding hand crossbows, I stand corrected. >>51001874

Thanks everyone for your answers, I do have one other question please.

Instead of doing the hand crossbow set up, what if I did a 2 handed set up with great weapon master and polearm mastery instead? I'd still be a fighter and battlemaster with precision attack for the -5/+10 option from my feat. Would this be even stronger perhaps?

>>51001969
Don't base your character on what sort of build would be stronger or weaker.
Speaking as a DM, if one character is unbalancing the action by being significantly better or weaker than all the others, then that is simply that character who will be getting the worst / best loot, to even things out.
It's impossible to build interesting combat-encounters for a party if they are at completely different levels of optimization, and because of that, I will bone you on loot, if you optimize your char. Simple as that.
So, build a character you want to play, because you want to play it. Don't sit around and try to make it as OP as possible.

>>51002192
>I will bone you on loot, if you optimize your char

wow, good job punishing player skill and destroying any agency your PCs might have

do you also expect the players to make stupid decisions because you'll punish them if they do anything smart?