What is the hardest OD Glock to find? Did they make fewer of one than the others, or are the more populars caliber harder to find? Maybe I asked the wrong question. I will try a more direct approach. I like the 9mm Glocks better from a ammo cost perspective, so I am focusing mainly on collecting them. The problem is that if I am buying OD for collecting and not going to be shooting them, are some more collectable than others?