Some G.43's were issued with a carrier with 2 spare magazines, but that was the exception. Mostly, they were issued with one magazine in the gun and the soldier loaded with standard K.98k clips. Almost all were made with a scope mount rail; they are very accurate and with the ZF4 scope make a good sniper rifle.
In yet another goof, Herr Hitler refused to authorize R&D on semi-auto rifles, feeling that the Mauser 98 of his service time was good enough. In addition, the first efforts (the G.41w and G.41m) just were not very good. For having been developed in a hurry and under pressure, the G.43 is not bad, but in overall quality and ruggedness the M1 is far superior, having had a lot more development time. The G.43 gas piston system has also turned up in the Armalite AR-180.
The FG.42 is not really comparable to the G.43. The FG.42 (Fallschirmjaegergewehr = Paratroop rifle) is a selective fire light machinegun, not a true rifle. To compare it to the G.43 is like comparing the BAR to the M1.
Jim