Board Thread:General Nerf discussion/@comment-27035444-20160910210507/@comment-27306930-20160911031136

If the stock O-ring is in reasonably good shape, just get some teflon tape from the plumbing section of your hardware store and wrap a layer or three in the slot the O-ring sits in. That will increase its diameter ever so slightly. Some people use electrical tape, but teflon tape is inherently slipperier.

As far as the batteries go, you got lots of options. Ask a dozen NerfHeads, get a dozen answers, but you can find a 4 AA battery holder at Radio Shack that can be wired directly to the terminals shown in that mod guide link I sent you. When it comes to batteries, I really like these On The Way Li-Ion batteries. But there are lots of others like these no name 14500s. Just google protected 14500 2000mAh Li-Ion cells.

Gonna need a 4.2v Li-Ion charger too. This NiteCore charger is the best thing I've seen in a long time. (Thanks again Mojo) But a lot of batteries like those SmartLive cells come with their own charger.

The screws, hmmm. You're on your own Spudnick. Here's a cool article on removing various stipped screws. I've also resorted to a simple trick - put a dab of super glue on the end of a screwdriver, touch it to the stripped screw head for a minute, and let it harden. Remove the screw then clean up the screwdriver with some acetone. Yes, it's a beech, but it works.