J - i've got a hand held lamp ( 1,500,000 ) with motorbike battery, bought some red plastic sheeting from local shop to make a lens. If i take the lens off it covers the field easy, too bright really but considering it only cost me about £15 all in i cant grumble ! Also when the dog gives chase i can see her no probs. As for the difference i think it's something to do with the pellet being lighter in the .1777 so goes further holding more of it's power ? Prob wrong, if i am i'm sure the keyboard warriors will be along shortly to put me right !