2.5-4% Bonus Critical Chance on Chained Hit. Stacks 5 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%.
5-8% Strength for every shot fired during continuous fire. Stacks 5 times.
This is just the build I run for Havocs, several points can probably be swapped around, especially field improv and marksman.