Fire Arms vs Crossbows

We're starting a new campaign where I'm playing as a level 5 Ranger who will multi class into a rogue for the rest of the campaign.

I'm trying to pick my level 4 feat and I'm stuck between gunner and sharpshooter. I know Sharpshooter is great even with the 2024 nerf and works for all ranged weapons, but Gunner would give me access to fire arms, which my DM said were allowed. The best he'd allow me to use would be the hunting rifle, which does 2d10 damage compared to the heavy crossbow's 1d10, which keeps on par with a wizards 2d10 firebolt. Yes i'd get two attacks, but that would be my "cap" on basic damage compared to wizards getting fireball and more at later levels.

The real question I have is, is the added range of sharpshooter worth more than the ability to use fire arms? A crossbow has a 400 foot range, so I could stay well out of combat unlike with a hunting rifle, but I'd be doing significantly more damage with the fire arms. If I went Gunner, I'd still take sharpshooter later, but I don' know exactly when.

Looking for some thoughts on if the added range is worth it compared to a higher damage? None of this is taking into account crossbow expert for the bonus action attack, which I'd take later if I stick with sharpshooting crossbows fyi