Hello there,

As per Wiki:

• Kuva Quartakk: Fires single shots in full-auto when fired from the hip; semi-auto fires four shots simultaneously while aiming; 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 (in a similar manner 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 to pick Heat as an elemental.

Some info about weapon:

• Near-equal physical damage distribution; effective against all factions
• Hip-fire shoots fully-automatic rounds
• Aimed fire shoots four rounds simultaneously in a burst
• Uniquely fires all four shots simultaneously instead of consecutively, reducing the chance of one missing
• Innate 0.5 meter Punch Through

This build will gain much more from combining your Warframe with Sentinel which will carry Sentinel Weapon with Vigilante mods on it. Even if your Sentinel dies, the Set Bonus will remain. Four Vigilante Mods gives you 20% chance to enhance Critical Hits from Primary Weapon.

Enjoy, THeMooN85