No, I use the stock bulb in my Magcharger so I do not need to drill and expand the hole. I used those more powerful bulbs in my other mod lights. I do not know if the socket of Magcharger can resist the heat of 5761? Probably not? By the way Fivemega has a ceramic socket for it.
I made a spacer by myself. Just use some brass screws / nuts and plastic washers (mine is PA6 / Nylon)... I can even store some spare bulbs in that spacer.
For those who have a Big Leef tailcap and would like to have some spare parts, here are the part numbers.
I am not sure if this switch is the original one used in the Big Leef, and I have not used it yet, but I have ordered a few similar ones including one that is suggested by a member...
This is the perfect replacment of the stock Nicad/NiMh battery.
Use stock Magcharger 6V halogen bulb (1.7A), over 3 hours of runtime.
If I need something more powerful / higer wattage bulb, I will go for other options instead of Magcharger.
The super long Kel-Lite BTL 26 is a 12C but it should be super heavy with 12 nicads.
Maybe a shorter Kel-Lite / Maglite with four li-ions?
Or a 3D with three 3AA serial adapters = 14.4V.
I am not sure if the stock lens / reflector / socket can resist the heat of a 12-cell bulb.