That works as a safety factor, too, because it would be next to impossible to load a double charge of Trail Boss. 243’s powder capacity and about 75 percent of the. 243 Winchester takes up about 60 percent of the. For instance, a minimum charge of Trail Boss for the. The powder also works well to produce slow velocities in rifle cartridges because its circular kernels with a hole in the middle are fluffy, and a charge occupies a good portion of a powder capacity in a rifle case. The powder was designed primarily for handgun cartridges shooting lead bullets at low velocity. IMR’s Trail Boss is the only powder I’ve found that works to achieve subsonic velocities in a variety of rifle cartridges. Loading heavy bullets with these powders, and a few others, lowers velocities even more, but then there’s the matter of suitable rifling twist to stabilize such heavy, long bullets at subsonic speed. Light amounts of relatively fast burning powders intended primarily for handgun cartridges, like 2400, Unique and Red Dot, come close but do not quite generate that velocity level. Powders suitable to attain such a slow velocity are very limited in cartridges such as the.

For the sake of argument, let’s say 1,100 fps is the speed of sound, and any bullet flying slower than that is considered subsonic. So I started a search for subsonic loads for a few of my centerfire rifles to see if there was any substance to bullets at subsonic speeds. The advantages of such loads, the posters type, are low noise and an absence of recoil, and I’m all for that. There has been a lot of chatter on Internet sites lately about centerfire loads that fire bullets at subsonic velocities. These loads and others were shot with Trail Boss powder in an attempt toĭevelop subsonic velocities (left to right). Author: John Haviland / Wolfe Publishing Co.

Load data subsonic 223