If I am correct, the GSG-9 (Grenzscutzgrupe 9-pardon the spelling) uses the MSG90. Most military units in the United States Army would use(if they were a sniper) the M21 or some SEAL units and even some Force Recon units are starting to use the M82A1. I have fired the PSG-1 and the M21, i actually prefer the PSG-1. Never fired the MSG90, but have seen them before. Like others said, get the new HK's by the lost brothers. Nice weapons.