.44 Magnum Barrel Length and Velocity Loss Graph
Graph by Jim Fleck
Many handgun shooters wonder how much velocity loss a shorter barrel entails. Guns and Shooting Online Chief Executive Technical Advisor Jim Fleck created the graph you see below to help answer that question. Years ago, the staff of the NRA's American Rifleman magazine determined to answer that question by building a .44 Rem. Mag. revolver with an 18" (carbine length) barrel. They proceeded to chronograph full power Remington, Winchester and Federal factory loads using 240 grain bullets (five each, for a total of 15 rounds) and average the velocity results. They then cut 1" off the length of the barrel (leaving 17") and repeated the chronographing. This whole process was repeated, removing 1" of barrel each time, until only a 1" barrel was left.
This is essentially a worst case scenario, as the .44 Magnum is a large, high pressure and high velocity revolver cartridge that is typically loaded with slow burning handgun powders (H110, W296, 2400, etc.). It, along with the other magnum cartridges (.357 Mag., .41 Mag., .454 Casull, etc.), should therefore show more velocity loss from short barrels than smaller, lower pressure cases loaded with faster burning powder, such as the .38 Special or .380 ACP.
Jim took the NRA's data and produced the graph you see below. Graphed, the barrel length / velocity loss relationship becomes visually obvious. (The vertical axis is Velocity in fps; the horizontal axis is Barrel Length in inches.)
As you can see, the curve flattens as the barrel length increases, meaning the rate of velocity change decreases as barrel length increases. The velocity difference between a 2" barrel (MV 935 fps) and a 4" barrel (MV 1165 fps) is 230 fps; the difference between a 4" barrel and a 6" barrel (MV 1298 fps) is 133 fps; the difference between a 6" barrel and an 8" barrel (MV 1384 fps) is 86 fps; finally, the difference between an 8" barrel and a 10" barrel (MV 1445 fps) is 61 fps.
This graph illustrates that the 2" and 3" barreled Magnum revolvers recently marketed for protection in the field are very inefficient. It is worth noting that the standard barrel length for the popular Ruger Redhawk, Super Redhawk and Super Blackhawk .44 Magnum revolvers is 7.5" (although other barrel lengths are available), which would seem a reasonable compromise based on this data. A 7.5" barrel is also about the longest that is comfortable for daily carry in a conventional belt holster.
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