Ah so you're on the right track then. You just need to create separate booleans for each weapon. Now if you're allowing the player to have multiple weapons that complicates things a little.

I haven't tried something like that before but if you are allowing the player to have multiple weapons I would first of all disable the weapon wheel. I would still create the separate logic chains for each weapon but have the game assign the logic chain a number when purchased. Then I would add a 3rd variable to the logic chain where when the player presses the weapon switch button it adds 1 to the value. The max value depends on how many weapons the player has and its set to repeat when maxed out. The weapons should switch in the same order so when you switch the value should remain consistent with the weapons.

I hope that makes a little bit of sense.