AKM74/2 BloodHowler

This battered Kalashnikov variant has survived countless emissions and firefights, its steel frame now fused with pulsing red growths like capillaries carved into rusted metal. When held, it thrums with a low, animalistic heartbeat. Said heartbeat increases it's run whenever it is pointed at a bloodied prey.
The weapon deals 2d6+your dexterity modifier of piercing damage on hit.

• Range: 120/360 ft

• Ammunition (reload 30), two-handed 

 

Burst Fire. When you take the Attack action and make an attack with this weapon, you must expend 3 rounds of ammunition to fire a short burst. Roll the attack as normal. On a hit, roll the weapon’s damage dice three times and use the highest result. (This means you can make 10 attacks before reloading.)
Bloodscent. When you hit a creature that is missing any of its hit points, the attack deals an additional 1d4 necrotic damage. If the target is bloodied (at or below half of its hit point maximum), this additional necrotic damage uses exploding dice. Each time you roll the maximum result on a die, you roll another die of the same type and add it to the total. This can repeat 5 times(for a total of 6d4), if the dice is rolled. If the damage is maximized by any way, it only deals 1d4 necrotic damage.

Zone Feedback. When you reduce a creature to 0 hit points with this weapon, you gain temporary hit points equal to your proficiency bonus.

Vex: If you hit a creature with this weapon and deal damage to the creature, you have Advantage on your next attack roll against that creature before the end of your next turn.

 *please ignore the Slow weapon mastery, it's not real and shouldn't be taken into account.*

It’s up to you to decide whether a character has proficiency with a firearm. Characters in most D&D worlds wouldn’t have such proficiency. During their downtime, characters can use the training rules in the Player’s Handbook to acquire proficiency, assuming that they have enough ammunition to keep the weapons working while mastering their use.

Notes: Range, Two-Handed, Ammunition (Firearms), Burst Fire, Reload, Slow