22 caliber is generally too small for effective sniper operations, 6.5mm is as small as I'd care to go. For my complete diatribe on this topic look at the duty roster at Sniper Country, in the archives from about three weeks ago, early August, late July posted as Ken M. FBI uses 308, the secret service used to use 7mm Rem Mag, but they switched to 300 Win mag according to what I've heard. Might be wrong. Ammo standardization isn't the big deal everybody claims it to be, it's the civilian tac reload of the sniper world. We get special ammo(currently M118LR) and if we don't get it, M80 SUCKS. You're better off using M855 from your M16A2 or M4 with the ACOG on it. Which we have to carry also, since a bolt gun in a fire fight is just dead weight for the most part. Semper Fidelis...Ken M