[IX-103]

That's not true. Preventing jams can actually require more complicated designs. To avoid jams the device should limit the range of motion a device is capable of and deal with dirt and debris. That can require additional parts to stabilize the motion, sealed components, specialized alloys to match thermal expansion, or more complicated motions that clear contaminants.

[bluGill]

Or you can step back to a basic bolt action that has less moving parts. The slow cycle times mean you can ignore thermo expansion - just let it cool.

[wredcoll]

I mean, maybe a musket has fewer jams per minute, but I suspect it has more jams per round fired.

Also, bolt actions aren't exactly the definition of simple.

[bluGill]

Given equal precision and alloys used in construction a musket will jam less than a more complex gun. However a musket and bullets built with 1700 technology/precision will jam more than a gun built to the best best modern standards standards (though there are some pretty bad modern guns out there too that may not stack up so well).

A bolt action is simple compared to any semi-automatic gun. Particularly if it is a single shot bolt action thus dispensing with the complexity of a magazine feed.