Im pretty confused...

[Rapiddragon]

On the paper,best overall weapon in the game should be puncture based weapon with toxin( or viral? ). Because puncture affects to all grineer enemy and toxin has shield ignore so it can deal with corpus no problem. But why most of the build has corrosive damage on it?? Is there any meaning on putting corrosive into boltor p??  Help me... 

[Plushy]

Im no expert but it might be because Grineer have armor and so do corrupted so that's 2 of the 4 major factions that are affected more by corrosive. I could be wrong though. I'm kinda a meh player  

[GinKenshin]

Corrosive is the best element against grineer and corrupted and the infested ancients. It's status effect reduces armour of enemies, which means extra dmg. I think that's why it's popular 

 

toxin does bypass shields and dmgs health, but it also is affected by armor?

[yetanotherunoriginalname]

Corrosive damage deals +75% more damage to units with ferite armor ( Carried by heavy gunners as well as most weaker grineer units,bursas and oxium ospreys). its proc,however, is the reason why it is so popular..because a corrosive proc permanently reduces armor by a certain percent. At high levels enemy units gain such a high amount of armor that  the damage you do becomes negligible (So weapons that can strip armor thanks to the corrosive proc will deal with them better and the boltor prime has a good status chance.). The only enemies resistant to corrosive damage are units with "proto shields" (bosses and heavy corpus units),as a result it can be applied to most factions. Lazy players tend to just roll with corrosive I noticed. Keep in mind there is no universal build that is going to be equally effective against all the enemies a tenno faces, and you`ll have to adapt your damage types to the faction you`re combating at the moment. Keep in mind you can strip enemy armor entirely by bringing 4 Corrosive Projection auras into a game. This will destroy enemy armor entirely leaving only their flesh. In such a scenario corrosive damage is worthless (since there`s no armor for it to work) and in that case its best to roll with a viral build (extra damage to flesh).

 

Edited March 22, 2016 by yetanotherunoriginalname
I`m such a slow typer :(

[gkuoni]

Corrosive basically shreds through armor by not only dealing increased damage to it, but actually reducing it to the point where you can deal base damage. Armor will reduce the total damage they recieve, so effectively removing their armor allows for them to be dealt with easily. The thing that scales on grineer enemies is the armor, their health stays the same (I think). This basically means that if you can remove their armor they will be no harder to kill than pinjatas.

The thing is that corrosive also deals increased damage to most of the tankier infested units, making them easier to kill too. This basically means that with corrosive you are mostly well off to deal with those enemies.

However Toxin and magnetic is recommended against corpus simply to remove their shields and also deal damage through their shields with toxin.

If you don't want to switch loadouts constantly and mods around, the best option is to stay with corrosive since it will still deal all around the best damage and is good for late game.

If you however want a more specialised elemental build against each faction I'd recommend (Remember, this is mostly meant for elemental builds/combos, base damages such as impact and puncture can also be built for but elements are usually your best option):

Against grineer:

- Corrosive on your primary or secondary and then viral AND radiation on your other gun weapon (melee as per preference or can also go corrosive if you use mostly melee)

Against corpus:

- Toxin and then, if you can (you will need two mod slots though) magnetic. Toxin will allow you to go through their shields and thus kill them quicker.

Against infested:

- Corrosive and heat/fire. Corrosive for the heavy units such as corruptors, fire for crowd control and also more damage to the weaker units. 

(You can use the infested corrosive set up for the grineer one with corrosive and then have all three versions)

 

This is however just my recommendation and the way I do it. You can experiment and try other elements such as gas too.

Hope this helped!

[Phatose]

I would only consider corrosive vs grineer on a status heavy weapon.  Without procs, corrosive isn't great vs alloy armor, and the most dangerous grineer units have alloy armor.  Radiation/Viral or Radiation/Cold for non-proc weapons vs grineer.