Standard Meusser shoots semi-automatic

As the title implies, the standard Meusser, atleast the 5C variant (though it shouldnt differ on the lower quality Meussers), shoots in semi-auto, despite the fact it says bolt-action.

This allows you to fire 5 .243 rounds in about a second if you’re quick on the trigger, before you reload.

Huh. That sounds… Fun, actually. But probably not intended. Any idea how this bug came to be?