Boring out a flashlight body diy style

I have two l2's one that was made for 18650's and a first generation one that didn't fit them. I moded the first gen one to fit 18650's with a few simple things that I had. I'm pleased with the results and thought i'd share how I did it. You'll need a drill, some kind of a spindle (I used a big drill bit with a long section of un-cut shank), emmery cloth in a corse grit, and duct tape. I started with sand paper but that tore up and wore down way too fast. Black 50 grit emery worked very good for me. Tape the emery to a spindle of some kind, roll it up till it's a tight fit in the flashlight body and then shim the middle of your roll to increase thickness. Ream out the body and successively shim the roll thicker untill you can pass an 18650 battery. Remove o-rings and wear gloves. It gets very hot. Finish off with a fine grit to smooth things out. I used a 320 wet paper to finish but this step is optional. Don't force a battery into a hot tube full of grit and aluminum dust. You'll ruin the wrapper. I my first l2 came with 2 cr123 extenders. I did those too. I suppose you can do this with any light if it has enough thickness in the threads. It's important that you shim your roll somewhere in the middle so that it makes for easy insertion in to the tube. The tapper makes it easier to control and it acts like a tappered reamer.

Nice. Now someone post this to CPF so that they may fix their Surefires.

Many thanks for this mod. Never thought to do it this way. Nice! I´ll take a look at my G2 again.

The traditional method is to use a brake cylinder hone, though I prefer this idea, cheaper for a start.

Man, that would take forever with a cylinder hone.

A G2 has a nitrolon body with a metal sleeve in it.
You first have to cut/remove the sleeve and than you can do the boring.
Beware: the remaining body gets pretty thin!

How to => DIY: Surefire G2 nitrolon bored for 18650 | Candle Power Flashlight Forum

@agenthex: they know :open_mouth:

This is the method I use most often. Drill bit, carriage bolt with head removed, hole saw, etc, any cylinder you can chuck in a drill or drill press. I gradually increase the bore by adding short pieces of masking tape under the sandpaper. It’s time consuming but the most accurate DIY method I know of. Old thread, wish I’d seen it three years ago.

Necro-thread, indeed. (I got a bit wistful seeing Don’s squirrel up there…)

But anyway, for what it’s worth, this method worked pretty well for me: Boring a D mag for 4-AA... hand tools only

(Might be overkill for a short light, though.)