I think it should have a +10% ammo consumption +20 metal upgrade and deploy requirement and if it kills someone it should give you 75% of the health it took from enemies and will automatically deploy if you die while hauling it but at 75% speed

tl;dr

pros: Auto deploys when you die while hauling a building but only 75% deploy speed
Rewards 75% of health taken on kill and 20% on assist
Projectiles fire 80% faster

cons:+10% ammo consumption
+20 deploy and upgrade requirement
Deploys 10% slower
Projectile reloads 30% slower
Bullets do 60% less knockback