I've been doing it also, no probems and a bit longer run time. Btw, someone asked if the head could be removed from the JR's body. Yes, it's threaded and comes off with a little effort. Strap wrenches work best. I found poor machining and lots of chips in that area. Thinking of machining up a single 123 body for it. I also have a bunch of Tadiran 3 volt lithium AAs lying around I could use if I had a single AA body. Hmmm..wonder what would happen if I put two of those in the normal tube. 6 volts may be a bit much for the JR...