The Blaster, Antigua, Magnus, and Autogun don't need to rely on switch shooting for decent effectiveness.
Magnus and Autogun can be used just fine with their obliterative charge attacks. Pile CTR for these guns and you'll be murdering whatever looks at you funny.
Blaster and Antigua have some okay charge attacks. Use whatever you want for those.
Oh, Pulsar will work too. I'm sure you know how that gun works.
Catalyzer is treated as a fun gun. It's only effective if your allies don't kill your target.
Now just wait for Bopp and Fangel to give you an in-depth explanation!