I utilized this gun a lot on previous playthroughs but this time I'm using only full auto weapons this time.


My question, does full auto work with the double shot affix of this gun? I was thinking it would just shoot faster but can't say for sure.

It actually works better, given how the two-shot works.

The second bullet is non-modified in damage regarding your various perks, but, both bullets are counted as one when calculating armour penetration. Given that all automatic recievers lowers the damage per bullet, you will get an additional unmodified .45 to calculate penetration, vs. having only one modified bullet in non two-shot weapons.

So, the higher your damage is per single shot bullet (e.g. rifleman perk for example) the less value you get out of that unmodified bullet.

Two shot is better the lower the weapon's final damage compared to it's base damage.

an automatic that halves the damage normally does 3x as much damage with two shot

a semi auto that has normal damage does 2x

A upgraded gun that does double damage does 1.5x

so weapons that have lowered damage from upgrades are best,

The fatman mirv mod reduces damage by a lot, so a two shot fat man with the mirv fires 3x more projectiles than a normal fatman with the mod.

So it's really only good if I havnt invested perks into full auto, which I did. So should I just keep it semi and change to a .38 or something and keep it for backup?

No, you should still invest in perks that support your weapon of choice. You will still get a bonus, it will just be less the higher your perk rank and modding, and the extra unmodified bullet still counts for penetration. It is the extra penetration which does the whole "magic"

Taken from the Wiki;

Perks don't weaken it, they are after calculations, only weapon modifications.

Yes, the legendary ability will stay and it will be more awesome imo.