At 200 yards the kinetic energy of the 50AE 330 Grn round is about half that of it's energy at the muzzle.
Using simple (very accurate) ballistic terminal energy equations you can work out that standing 14,790 yards from the muzzle of a 50AE DE pistol is safe, unless of course one of the few millions variables don't quite stack up in which case I'm sorry you got killed but it was going to happen one day anyways as anybody standing at the dangerous end of a firearm for fun is a dumbass.
240,647 mean miles, so if you happen across a nice place to holiday on the moon you will be fine.
In more effective (and slightly less tongue in cheek version) if there is a chance a laser of any kind (above 1 Mw) can shine into the unprotected eyes then IT'S NOT SAFE. There are wayyyy too many variables to state an absolute safe distance by calculation other than the example above of the moon.
Great info Mac, the only drawback is if the end user assumes the label saying 30Mw on their pointer is correct, if that 30 turns out to be a 75 or 100 then the numbers don't work
If it's been piled then great but even then the thought of potential eye crossing leaves me cold.
The problem comes when fact becomes rumor, Guests read that a 30Mw laser is safe at XXX range and pass that on to their friends without the caveat of "BUT only if it IS truly 30Mw" so eventually the fact becomes "30Mw lasers ARE safe at XXX range"
When one of the guys here says "My laser is 33.23891 Mw" I tend to take that at face value being pretty sure it's been tested to like 20 million decimals When the 12 year old over the street who has a green pointer says "It's only 1Mw" I'm pretty sure he has just read the Ebay label