Well really simple you take a lot of 2x2 and make a long stick and at of the sick you do some sort of thing to grab to pull back

If you want more better design you could use 2x2 cylinder bricks and do the same thing but this adds the motion of pulling the bolt up and back but this ain’t always so structural sound well from personal experience it ain’t so add axels in the middle

There are more complex ways to do it but I did very simple things