hi guys,
Carley 717 will take four 123 batteries safely. The Carley 809 potted is very robust and will take five 123's with no problem, but them you will have to use a Maglite 4 C and put a extension spring added by solder to the stock one.
The Carley 808:I never have the opportunity to try it as they were out of stock the time I ordered.
I have only one packet of 3 717 which I will part for $24.00 shipped.
Shaving the skirt means take a razor blade to the skirt of plastic wrapping that wrap over part of the negative contact, after you slice that out, the entire diameter of the battery is exposed.
If you need more clarification, ask and I will take a picture tomorrow.
Also you can take the positive top (nipple part) out of a C battery and use that between the last battery and the spring.
The increased resistance is minimum.
Guys, the starting voltage of the 123's from Surefire is more than 3 volts, maybe around 3.3 volts for each. So it is recommended that you don't use FRESH BATTERIES, run them in another light for 5 to 7 minutes FIRST.
Juan C.