I would assume the law applies for factory ammo and not for one that uses a handload that said handloader claimed to meet the the requirement. The latter doubtful IMO.
The regulation states "as rated by the manufacturer." If you reload, you are the manufacturer. If in question, the warden could confiscate your ammunition and firearm and test it. Which I doubt would happen unless you were trying to prove your 9mm super ++++P++++ shot from your Shield was legit.
It's one of the dumbest regulations that exist IMO, specifically the part that says at 550ft-lbs at
50 yards. Up until a few years ago with the advent of LabRadar, it was not possible to measure bullet velocities anywhere other than the muzzle. Ok, fine you could attempt to shoot through your chrony ears from 50 yards away...only to find out your were just a little too low and took out the entire unit. Why not just say 650ftlbs at the muzzle? It's a 1000 times easier to measure and verify. The second part requires the barrel to be "at least 4" long." Why does that matter? If I can get 650ft-lbs out of a 2.5" Ruger Alaskan in 44mag or 480 ruger, what difference does the barrel length matter? Colorado law already states, very clearly, that you can "conceal carry a firearm while hunting without a concealed carry permit," so it's not a conceal carry concern for the wardens.
