Up to +5-20% Strength based on the charge time of your heavy attacks. Stacks 3 times.
+12-24% Rending on Enemy Weak Spot Hit for 3.5s. Stacks 5 times.
Critical hit chance scales by your current heat level up to 27.5-50%. Also increases critical ranged attacks damage by 4-10%.
Up to +7.5-20% Strength scaling with Heat Level.
Alternatively, take a Bolter with Cavalcade, Pinning Fire + Flak and Unyielding.