The default rocket pods are fine. They deal good damage, got decent accuracy, good range, very good fire rate, can effectively hit critical spots to kill enemies quickly and given the fact they’re dealing explosive damage they’re not even situational etc.
However that’s pretty much the only Iron Bear weapon that universally works on Mayhem4 making all the other weapons seem pointless.
Normal mini gun: No splash damage, high fuel consumption, much lower damage/damage per second. Result: Useless.
Cryo mini gun: No splash, not enough damage generally, elemental weapon making it overall situational. Result: Useless.
Explosive mini gun: Takes a while before you can even start shooting unlike the default rocket pods, overheats quickly, takes too long to cool down, deals the same damage per shot as the rocket pods BUT deals by far less damage per second due to the fact the rocket pods shoot in 3 rocket bursts. Result: Useless.
Salamander flamethrower (all variations): Forces you to fight at close distances causing Iron Bear to get damaged quickly by mobs and stronger enemies, deals pretty much no damage on Mayhem 4 despite the highly limited range and is situational due to the element. Result: Useless.
Grenade Launcher (all variations): Good overall damage and good splash range. However slow fire rate, can not EFFECTIVELY critical-shoot enemies unlike the default rocket pods, deals by far less damage per second due to the much slower fire rate, limited range and limited accuarcy. Therefore result: Useless.
Debuff rockets: The debuff is not strong enough, the reload speed is ridiculously long, worse accuracy than default rocket pods, low magazine size. Result: Useless.
Nuke rockets: 1 shot magazine, low damage, elemental/situational, very slow reload, extreme fuel consumption, can’t even one-shot-kill small enemies. Result: Useless.
Railgun (fire): Elemental/situational, high damage, no splash bonus, slow recharge speed, requires 100% precision. Result: Not completely pointless but way too situational compared to the default rocket pods.
Railgun (electricity): Works like an oversized Brainstormer which is nice, no splash bonus, slow recharge speed, elemental/situational, requires 100% precision. Result: Not completely pointless but very situational just like the fire railgun and therefore just worse than the default rocket pods… Again.
Railgun (corrosive): 3 shot bursts, splash bonus, elemental/situational, currently bugged causing crazy high fuel consumption, decent damage. Result: Decent but still much worse than using default rocket pods and thus kinda pointless.
Iron Fist (all variations): Forces you to attack one enemy at a time just like the Salamander causing Iron Bear to take damage quickly, deals little to no damage on mayhem 4, no splash bonus, very slow attack rate. Result: More than useless.