I can see why you’d be hesitant to compare it to some of these things, but the issue isn’t simply Molten weapons. Everything seems to suggest that the Pew-Matic is worse than many of its competitors: Demon/Tendon Bows, Boomstick, even Minishark all do substantially better than it (remember that Queen Bee is a terrible boss for Minishark due to her defense spiking, and still got faster times). It simply doesn’t cut it DPS wise. Furthermore, I can see why it shouldn’t be compared to Phoenix Blaster, but Molten Fury is simply more available (comes right after an easier boss boss tiered earlier). Pew-Matic could really just use a good DPS buff, especially considering it doesn’t fare all that well to a couple weapons that come *before* it.
. . . how are you getting that Pew-Matic underperforms Demon Bow/Tendon Bow? Is it an accuracy/range thing? Because no matter how I look at it (with Demon/Tendon Bow using the best possible arrows), they still fall short of Pew-Matic's DPS. They aren't even autofire like Pew-Matic, so they are going to be falling even shorter generally speaking.
Are you including Archery Potions in the considerations here? That's the only thing I can think of which would be leveling the playing field in that regard.