So I've been running my Knight as a gun-toothin' desperado. I picked up a Magnus and got it upgraded to a Mega Magnus and I'm fairly satisfied with it. Problem is that there are some things that it just won't blast to smithereens such as those jellies. I currently run around with an Autogun as a backup gun for those (as well as clearing lots of bushes/blocks/gathering minerals real fast!) but it is losing it's edge.
So I'm wondering: if you're stuck to two guns, and one is a Magnus, what other gun would you pick?
If you want a gun for Jellies then the Biohazard path for the Catalyzer or a Shadowtech Alchemer is what you want to look at. If you want more power against Constructs then you'll want either the Polaris path for the Pulsar or one of the other Alchemers (Firo, Cryo, Volt)
If you want a Normal damage gun then you have the choice of the alternate paths for the Pulsar and Catalyzer or the Blaster line.
I'd assume you could use an Autogun against most of the bigger, slower constructs so maybe you want to focus on Jellies and go with a Shadow damage weapon?