Nope.
Bozar is stronger that
Gauss Rifle.
Bozar damage: 25-35, burst rounds: 15, AP requirement: 6;
Bozaar ammo mods: AC -20% DR -20% damage mod 1/1
Gauss Rifle damage: 32-42, AP requirement: 5;
Gauss Rifle ammo mods: AC -30% DR -20% damage mod 3/2
Advanced Power Armor mk. II Damage Threshold: 18.
This means that, after we apply the damage, damage modifier, and burst rounds in formula in favour of the small gun (because I know it's way weaker), Gauss Rifle inflicts 36.5 damage on average per bullet, and Bozar inflicts 12 damage on average per bullet, not counting DR (or miss chance) in both cases. In bursts of range more than one hex against a single target (the worst case here), just 1/3 of the bullets have a chance to hit. In the Bozar's case, it's 5 bullets out of 15. This means 50 damage opposed to Gauss Rifle's 36.5. And to round up my victory, it's 37% more damage. Also, in point blank bursts, Bozar does 3 times more damage. And I don't think that the bonus 10% AC reduction from Gauss Rifle's ammo makes up for that, especially given that in the lategame, people have enough skill for 95% hits all the time.
That damage is in case all the bullets hit. But Gauss Rifle can miss, too. So on average, it's affected by miss chance in the same way. Also, Bozar's bullets are way easier to find (though Bozar uses more bullets). And Bozar is much more powerful against enemies with less armor.
So much for the Bozar vs Gauss Rifle case. However, small guns are better than big guns until the mid/late game. Frank Horrigan has 2 more DT than APA Mk. II, but it's still 50 damage for Bozar, and I'm too lazy to calculate for Gauss Rifle (though it's certainly less than 36.5, so it's inarguably still weaker than Bozar).