The G-43 is an improved G-41 in which the rather wonky and heavy gas system of the G-41 was replaced with a short-stroke piston that was nearly directly copied from the SVT-40.
In addition to modifying the gas system, they also added a 10 round detachable box magazine and a scope rail (for which a small number were fitted with the ZF-4 scope to serve as designated marksman rifles).
The G43 is so mechanically similar to the G41 that a large number of the parts are entirely interchangeable. Both rifles