Having always either been issued or carried my own Sig pistol as a police officer, I decided to make the switch to Glock and ordered and received my brand new Glock 22 and 27. Both guns are completely stock except I installed Meprolight night sights on each pistol without a problem and went to the range to get them sighted in with our required duty load, 180 grain Speer Gold Dots. Both pistols shoot unacceptably high, approximately 5.5-6 inches at 25 yards. Meprolight advises that they don't have any shorter rear sights for the pistols, and they suggested I contact Glock about the problem, since it sounded like a "lock up" problem. Glock says to send the guns to them so they can figure it out. Is this a common problem with Glocks? I realize different bullet weights shoot to different points of aim, but changing ammo is not an option here. Anyone experienced a similar problem? If so, what was wrong with the gun? Thanks in advance for your opinions.