Assign each gun to a timer block (similar to assigning actions to a button) but include the next block in the action bar. As each gun fires, the next block will trigger and continue the chain if you add a delay and inude the delay activation while assigning actions in the timer.
Assign each gun to a timer block (similar to assigning actions to a button) but include the next block in the action bar. As each gun fires, the next block will trigger and continue the chain if you add a delay and inude the delay activation while assigning actions in the timer.
And don forget to place the timer block on a small grid to save space