Hello there,
As per Wiki:
- Kuva Brakk: Higher rate of fire, magazine capacity, and shorter reload time
- These weapons have a max rank of 40. To obtain the maximum rank, the player must polarize the weapon five times, with each Forma increasing the maximum possible rank by 2 (similarly as the Paracesis).
- All Kuva weapons deal innate elemental damage in addition to physical damage. The amount of this damage is random, ranging from 25-60%, while the type of element is determined by the Progenitor Warframe, as per the table below:

According to the above, I added exactly 5 forma to this weapon, so we can obtain Mastery Points from it.
In this case, I recommend picking Magnetic as an elemental.
Some info about this sidearm shotgun:
- Very high Critical Chance
- The highest overall Status Chance of all secondary shotguns
- Very fast reload speed
- Innate 0.5 meter punch through
- Ammo efficient
- Has linear damage falloff from 100% to 4% from 10 m to 20 m target distance (distances are affected by projectile flight speed)
- Wide pellet spread cone makes the weapon ineffective beyond medium range
- High recoil
The [Steady Hands] mod on Exilus is here to reduce that high recoil by 60%.
Enjoy, THeMooN85