What weapon mods TO use on certain guns

That info can now be found in the MP Manifest Backup, here: isitaboutmycube.com/shelter/resourcelibraries/topic/467220-the-me3-mp-resource-library/index.html

Direct link to the corresponding thread: isitaboutmycube.com/shelter/resourcelibraries/topic/440103-must-read-how-to-determine-if-bugged-weighted-gun-mods-are-weightless/index.html

Although the backup is neat and time-saving, for the sake of completion and ease of access I think a sticky of copy-pasted threads from the old BSN here could still be of use. But that should be organised in some way, so that two people are not copying the same thread at the same time...if you understand what I mean.

Not going to claim it's optimal but what I like to use:

-AP on Reegar. Both barrel and ammo. It owns against everything else but I feel compelled to cover its weakness against armor as much as possible. Someone will probably show me up for how incendiary is better, I expect.
-AP on PPR. Same as above only not as drastic. Obviously mag size for mod. I also exclusively use this gun on Destroyer with Devastator so I'd probably suck with it on anything else.
- Cryo IV on Falcon. Makes it an insta-freeze gun for unshielded mooks. Slows down armor quite a bit and sets it up nicely for full frontal flaming.
-Disruptor and/or Phasic on the hard hitting snipers (Widow, BW, Javelin)- they're already awesome against armor, might as well boost shields.
-Smart choke on Graal- snipe with spikes yo.

In general I'll take extra ammo mods on just about everything and damage barrel as the other unless it specifically benefits from piercing (or there's a damage+piercing barrel of course), or it's a melee character (Shadow, Warlord) and then I just melee all the things.

Would need a long treatise for this since mods for whatever weapon depend on ammo choice to a large extent and that can depend on character and enemy faction.

Above point about AP or Drill combined with piercing mods on weapons without innate penetration is a good one. If you do that then cover penetration will occur with a damage penalty, unlike if you were to use no piercing mod + AP or Drill. Innate penetration weapons will always do full damage hits through cover regardless of mod (at least in current version of game).

I prefer some amount of cover penetration whenever I am in a match which means either AP / Drill or a piercing mod for the vast majority of weapons. Since a lot of automatics (especially AR's) like magazine mods, that usually limits me to AP/Drill + extended barrel and magazine.

Any "infinite ammo" weapon (recharging clip / overheat mechanic) should get magazine upgrades.

Hurricane Mag/Heatsink vs Hurricane HCB/Mag with AP ammo on both is essentially a wash in sustained DPS. The later has a little better burst, the former gives you more total ammo.

Always run Smart Choke on hitscan shotguns with the exception of the Crusader. I don't personally run it on Graal since I prefer HCB and spare clips.

Phasic is mostly just useful on high damage per shot SR's (Javelin, Widow, Black Widow). In very specific instances Warp IV might be better.