Why do ammunition companies back off the velocity of cartridges? Perhaps for safety is one reason in older guns?
Perhaps. At least that is probably what they would say. My suspicion would be that it is mainly to sell newer calibers. From a marketing standpoint, rifles are too well made and last too long. (Some of the newer designs are unlikely to have that problem, though!) New cartridges, redundant though they may be, are one way to sell new guns. In some cases the change in catalog velocity is due to the availability of inexpensive chronographs. Many of the old velocities were taken in 26″ test barrels built to minimum specifications, and when consumers got access to chronographs, they found that factory loads did not deliver the advertised velocity in their hunting rifles. Such a stink was raised that a couple of decades ago the ammo manufacturers revised their testing procedures, changed the standard barrel length for most rifle calibers to 24″, and started printing more accurate catalogs. Around the same time they also lowered the pressure to which some of the established cartridges were rou
