Kind of new to H&K but liked the USP I bought so I might have gottent taken. I bought a rifle I was told was an HK91. It came with an extra barrell, 9 mags two extra buttstocks and recoil springs all for $600.00. Obviously when I got it it's receiver was stamped Century Arms, however The barrel has an HK stamp and it also came with an interesting trigger group that was not in the gun. I had a friend look at the whole thing and he said their were some HK91's imported by Century when the old ban took place that did not have a certain portion of the full-auto receiver disabled. According to this friend these guns were grandfathered by the ATF. I have fired the gun several times now and love it (it is thank goodness semi-auto) but the trigger group that came with is supposedly full auto enabled so that if I got my class3 all I would need would be the sear to fully enable that function. Have been taken for a ride?