Algodoo

options --> simulation --> simulation frequency: increase it from 60 Hz up to 180 Hz!

Oh, and it is a very good work! thumbs up! =)

I agree! Very cool!

look at my lucky chance
i will rate your last uploaded scene

The mechanism functions smoothly as it is. Here's my advice for some tune-ups.

Make the dark pink and light pink boxes frictionless.

Resize the dark red-orange box behind the first bullet to match the height of the blue ejector box (keep the length the same).

Increase the force of the thrusters; the higher the value, the faster the reload. (Pro-tip: triple-click on one to select all alike).

Thanks you for the advice! @BLiu1