This article is already 20 years old, nevertheless RedWolf Airsoft reposts this article on using a Coke Can for a Poor Man's Chronograph if there is no chronograph available to use... "Not everyone can afford a chronograph to test how much juice their favorite airsoft pistol or AEG has. Even after lots of modifications you wonder how much velocity you're really getting. Well you don't necessarily need to dish out several hundred dollars for a chronograph. In most cases, a simple soda can is all you need to gauge those major power milestones.

First, get yourself a regular EMPTY soda can and rinse it out. Coke and Sprite cans work the best as beer cans and other brands sometimes have varying thickness which can throw off your estimates completely. Through experience, I've found Coke and Sprite cans to be fairly consistent in strength around the world. There are three major surfaces on a soda can that represent increasing strength and thickness; the side, bottom and top, in that order. While the sides are quite easy to crease and crush, you'll probably be surprised that they're fairly resilient to abuse from an AEG using 0.2g BBs. A standard unmodified MP5A5 will have trouble piercing even one side of the can. However, if you press down and flatten the surface a bit, you'll find it fairly easily to penetrate, even with a spring pistol shooting at 0.3J! For our sake of measurement, you are not to alter the can in anyway prior to the test. The naturally rounded surface provides the extra bounce to resist standard airsoft fire at 3 feet. When using the soda can as a chrono, hold the can FIRMLY about 3cm - 5cm away from the muzzle of your gun, being careful to place your fingers strategically out of the line of fire. You also want to be careful about richochet so wear safety glasses and use as few fingers as possible to hold the can so as to reduce the chances of getting hit during testing!"

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