This is my current setup for fighting the Corpus. It is very cheap, does not require any Formas, and most mods (except for Split Chamber, which I got by sheer luck) should be reasonably easy to get.

Following is a brief explanation for each mod:

• [Infected Clip], which provides you with Toxin damage, allows you to bypass Corpus shields and deal 50% more Toxin damage to Corpus crewmen of any type (total of 192.5 damage in a non-critical hit).

• Serration is there just to boost the damage of everything.

• [Split Chamber] greatly increases the total damage dealt with a single pull of the trigger, since it has a chance of spawning multiple bullets per individual shot. In general multi-shot is a good way to increase damage on a weapon.

• [Point Strike] takes advantage of Dex Sybaris' large critical chance and amplifies it significantly, making it highly likely to deal a critical hit.

• Finally, [Vital Sense] takes advantage of the high critical chance provided by [Point Strike] by increasing the amount of critical damage per critical hit. So, you will not just almost always get a critical hit, but you will almost always get a critical hit with 4.4 times as much damage as a normal hit.

Placement of the elemental mods (especially [Cryo Rounds] and [Stormbringer] is important!!! Otherwise you might end up with different primary and secondary damage types!

Once you are farther along in the game and are willing to dump time and resources into the weapon, you can use two Formas to add a rank 2 [Cryo Rounds] and a rank 2 [Stormbringer] (use one forma for [Split Chamber] and the other for [Serration]). This adds magnetic damage, which deals 75% extra damage to both types of Corpus Shields. With this setup, an average hit deals 4,187.1 damage.

If you are even farther in the game and have unlocked Riven Mods, you can replace [Point Strike] with the Rifle Riven Mod and two extra Formas (use one for [Infected Clip] and one for the Rifle Riven Mod) to significantly boost damage, critical damage, AND critical chance (with a cost of reduced zoom, if you are willing to make the [Sacrifice]). Even though you remove [Point Strike], this setup alone has a higher (97~98%) critical chance. With this setup, an average hit deals 12,985.4 damage. Also, you still have 5 capacity left over, so you can upgrade [Cryo Rounds] or [Stormbringer] to max and the other to one notch below max (I would not recommend wasting 4 capacity points on a measly extra 10% critical chance - [Point Strike] does add a base 20% critical chance, but any critical chance over 100% is wasted. It is much more effective, then, to upgrade actual damage mods). With the [Cryo Rounds] and [Stormbringer] upgraded, an average shot will deal 16,463.7 damage. HOWEVER, since you can first equip the Rifle Riven Mod at MR 8, you will probably already have weapons better worth the effort.

Please note that the damage reflected here is not exactly identical to the actual damage in game - for whatever reason, there are some minor variations between the two. Overall, though, the damage is still roughly the same.

Also note that [Dex Sybaris] requires mastery rank 7. However, it appears you are able to use it before you reach MR7 if you obtained it from the 7th anniversary quests.

Please let me know in the comments if you have any comments/suggestions, or if you would like to see the additional two higher-damage setups I mentioned above.