During the designing of the Beretta AR70 and Sig 540, both Beretta and Sig teamed up at first to design one rifle. The design team included two American engineers. The Americans wanted a multi lug bolt like the M16 because they claimed it was more reliable in design because the bolt didn't have to rotate as much as having larger bolt lugs. Both Sig and Beretta rejected the multi lug bolt design because they claimed it would hurt accuracy by not being able to always get even loads on all of the bolt lugs. They both went went to two lug bolts for "accuracy", because they felt even lug contact was possible with two bolt lugs. I would have rejected the mutli lug bolt due to not always being able to have even bolt lug contact, but my reason would be the strength would be weaker with higher bolt lug loads on less then all bolt lugs.