August 17, 2011
Measuring a Shot String With High-Speed Video
By Phil Bourjaily
This week’s Gun Nuts clip features some high speed photography in an attempt to answer the question, “How long is a shot string?” The high-speed videos allow us to measure shot string either by comparing them to the hashmarks on the wall, or by measuring the interval in milleseconds between the first and last pellet strikes. The answer, in both cases, is around 6-8 feet.
As I mention in the clip, the system is a huge improvement over the one used by my predecessor Bob Brister, who built a target stand on a boat trailer and had his wife tow it past him at 35-40 mph while he shot at it. The 18-foot long sheet of paper often showed lead payloads strung out from one end to the other. Pictures of the trailer and of many of the patterns Brister shot can be seen in his classic book, Shotgunning, The Art and Science, and are well worth a look.
Most of Brister’s work was done with lead, while these two videos show hard non-toxic shot in flight. Because steel and tungsten iron pellets aren’t deformed by the acceleration of being blasted out of a gun barrel the way soft lead pellets are, the strings are much shorter as the pellets are more uniform when they encounter air resistance flying downrange. Even so, they string out as they travel downrange because the pellets at the rear of the payload are drafting behind the ones in front and so retain velocity better.
The belief persists that a long string is an advantage because the trailing pellets can hit a bird if you shoot too far in front. Maybe every once in a while it happens, but I wouldn’t count on it. Remember, it’s the width of your pattern that gives you margin for error, not the length of the string.