I printed this cutie but not before remixing it a bit. was not easy. this model has many tessellations. you can see in the pictures i've added recess for the screws and I replaced the spring with a rubber band (in black behind the trigger) giving me full range of motion. Printed in PLA+, Marble texured for the outer shell and Orange for the inner working parts. Works like a charm.
For zero friction, I've Added a small pulley behind and inside the trigger and added a groove for the rubber to run inside it.
Still considering replacing the screw lead with one which keeps rotating clockwise whether one pulls or releases the trigger.
The author remixed this model.