Algodoo

What is the point of making the internals the same color as the background? I can't see anything unless I modify the color

The design is good though! There's a better way of making the barrel attached to the bolt, it involves allowing it to tilt. There's a Russian guy who makes paid, incredibly detailed animations of guns, and he uploaded a video of this mechanism (i think it's his son lol)

https://www.youtube.com/w … tAKZsXkEc0

I have a bunch of feedback though:
-Make the internals darker or of another color please
-Use very high densities on everything. More than 500 is fine. The critical parts (parts that do much force, like bolt face, sliders, the bullet shells) need to have 1 kg or more mass. You can make this gun work at 3 times the speed at 120 Hz, I'm sure of it!
-Avoid polygons wherever you can: use boxes. Box-shaped polygons won't work! Only boxes (if you right click it it should say Box)

I have more to say, but you're really good at guns if you managed to make one work with the stock density!

Thanks for the feedback, though, I decided to delete it in favour of a new caliber carbine.

Well, not delete it, but replace the scene with the caliber list.
Also, I'll likely find your advice very useful.