It is a G3 albeit one that has been accuarised by the factory,this variant is a step below the famed PSG-1.It is a wonderful weapons design that has been around almost 50 years ,the Germans designed them out of necessity after WW2 because the Belgian owners of FN were still hostile to Germany and would not cooperate with their intention to adopt the FN-FAL.  The design began as the CETME but was later refined ,the G3 and the MP-5 are by and away the most successful of this lineage.