I always use a full auto pipe rifle. .38 ammo is usually absurdly plentiful and when it stops being plentiful, I have weapons that use the plethora of other ammo types in game. My 10mm is my go-to pistol of choice, only switching to my .45 modded pipe pistol when 10mm ammunition is low, and either a revolver or pipe revolver as a last resort. Of course, there is also the combat rifle and the laser (rifle) which I mod to be automatic rifles. The former generally has rarer ammo but the automatic mods hit really hard.

In general, I use my full auto weapons for long range combat, where damage bleed off seems fairly severe in this game, so more weak bullets > a few strong bullets. In CQC, I tend to perform better with hand guns. Hip fire in this game is awful (and I don't have access to the hip-fire perks) so it isn't really about which gun has better hip fire in CQC, just which one gets the most bang for my buck. If I can kill a dude in a single shot with my pistol, it is automatically better "DPS" than a full auto weapon that takes 2. Of course, the rule applies to sniper rifles too, but I'm not much of a fan of sniper rifles, they're just not satisfying to kill with.

Don't get me wrong I want to use automatic, they are more fun but going through 400 ammo on bullet sponge enemies really svcks...

Using rifles seems to be the only way to keep a positive ammo income while looting.

Full auto is fun, but the loss in per-shot damage and the drain on ammo make it worthless to me.

My playstyle usually sees me sniping anyway. If I can't kill an enemy in one hit, I switch to a 10mm semi at closer ranges.

Full auto weapons are great on followers, but aside of that I don't like them.