This is a discussion on Misconceptions of Gun Testing within the General Firearm Discussion forums, part of the Related Topics category; First of all I'd like to think I could shoot as well as my wife - these are her targets. The revolver on the left ...
First of all I'd like to think I could shoot as well as my wife - these are her targets. The revolver on the left is an S&W 19-2 converted to the Phillips System with a shortened hammer throw, vented barrel, iron sights, plate gun. The one on the right is the Medusa that was tested by Popular Mechanics.
Before someone stole my Ohler chronograph in 1985, I got some semi-unpredictable results from gun/ammo testing. The first myth dispelled was the energy difference between a revolver and an auto. Common knowledge had it that a revolver would produce lower velocity numbers than an auto, shooting the same ammo, because of the barrel cylinder gap. Wrong. I got consistent results showing an increase in fps from the revolver over 1,000 rounds. The barrel gap was a hair less than 5 thousandths of an inch and I consider 3 thousandths really tight requiring frequent cleaning to keep the cylinder from dragging. Ammo was factory 38 Super fired from a Colt auto, and then a S&W Medusa conversion. The increase was 75 to 110 fps depending on the ammo manufacturer.
Number two was about printing. I always thought that a .357 would print higher on the downrange target because it would just zoom down there faster and bullet drop would be less of a factor ballistically. Wrong again. It seems that the slower round is in the barrel longer during recoil and that makes the round print higher. These tests were performed using a Ransom Rest (also stolen) using factory .380, 38 S&W, 9mm, 38 Spl, and .357 in the same Medusa as the previous test. This didn't explain why some 9mm brands printed lower and to the left unless barrel twist rate, lands and grooves, bullet weight or internal barrel diameter were factors.
Something to think about.