I'm pretty serious about killing carpenter bees around my shop. They bore holes in the fascia boards, and generally undermine the strength of any outside wood. The fly swatter has always been my favorite tool because it's light weight and quick. It swats them out of the air before they know what hit them. Most days I walk out on the deck and wait for them to come check me out. At first they are pretty dumb and hover right in front of me. Problem is, after 8-10 kills they get smarter and stay a few feet out of reach. A few years ago I made a spring loaded wooden gun that shot a light weight disk with about 50 nails protruding from it. It wasn't completely successful, but I did manage to impale a few bees with it.
My latest weapon of choice is low tech shotshells in my 357 magnum revolver. I use my usual 38 special powder load, pack it down with a wad over it, then add 75 gr. of #9 bird shot covered by another wad. A rolled up piece of paper surrounds the shot in the case. After crimping the case, I drip 5 drops of wax from a burning candle on top to seal it all up. The wax runs under the crimp so the ball of wax is captured making a pretty neat package. The picture below shows the pattern I'm getting at 8 ft. I still use the fly swatter when I can...those are freebies. But when they are out of range, it's well worth the nickel it costs to shoot them down.
Yeah, I know...there's something that's just wrong about blasting bees out of the sky with a 357 magnum revolver....but it sure is fun!