I have shot literally cases of Winchester NATO Ball, and all the IMI "Black Tip" carbine ball, +p and +P+ I could afford, through S&W, HK, Browning, Colt, Ruger, Kimber, Glock and SIG handguns. There were/are no issues or problems of any kind. I continue to do so. Both the white and tan box Winchester NATO ammunition produces the same average velocities in my guns. Velocities average, very generally, about 50-100 fps higher than standard 9mm ammo in my guns. Most, if not all, 9mm pistols sold through retail channels will have literature/owners manuals saying to use SAAMI spec ammo only (for obvious liability reasons). Pistol manufacturers may provide different information to police and military users. I'm surprised to hear that Glock doesn't recommend use of NATO ammo. I believe Glocks have a NATO stock number. I have a copy of an old bulletin from Karl F. Walter, then a Glock V.P., and addressed to " U.S. Law Enforcement Agencies ". In the bulletin, Mr. Walter discusses use of NATO,+P and +P+ 9mm ammunition in Glock pistols. Mr. Walter writes, " This type of ammuniton does not exceed maximum NATO specification pressure levels and is totally compatible to be used in Glock pistols." He also mentions that, " The pressure range of 9mm ammunition ( commonly available on the U.S. commercial market ) is primarily produced to extend the service life of pistiols that do not meet NATO endurance test specifications, hence limiting liability risks for certain ammunition and pistol manufacturers." I haven't read my SIG owners manual lately, but I know that in the SIG Armorer trainings I have attended, every instructor has told us that all commercial SAAMI spec and NATO ammo is approved for use in SIG pistols.