the .45ACP (Automatic Pistol Cartridge) make a MOST EXCELLENT "Plug" style Cigar Cutter. The size is perfect for a wide range of cigars.
There is a little trick that I use though, which greatly improves upon the original Plug style cutter. It is very simple but I have yet to see a manufacture actually use it!
I made this at TechShop Menlo Park
Read on, if you are a cigar smoker that happens to have access to spent cartidges :-)
Step 1: Find a .45 ACP cartridge (spent...), check it for roundness and condition
Find one that is nice and round; My sample is here is from a very high quality round; it is a nickel plated brass cartridge.