Ammunition and muzzle pressures

[dsp04]

Does anyone know the differences in muzzle pressures between ammunition with a normal amount of pressure versus subsonic ammunition with reduced propellant?

[0reo]

It's not quite as straight forward as that. It's not just a matter of "less powder". A powder that performs well at supersonic velocities usually isn't the best choice for subsonic velocities and vice-versa. Different powders burn at different rates and that also has a direct relationship with muzzle velocity and chamber pressure. I could use the same charge weight of two different powders and get very different chamber pressures and muzzle velocities. So, one would expect that a subsonic load would have less chamber pressure then a supersonic load in the same cartridge & gun but there's no way to know how by how much unless formal testing is done. I think there are a few places that will perform this testing but it is quite expensive.

Keep in mind, actual chamber pressure is affected by a LOT of other things I haven't mentioned here. I kept the answer as simple and direct to your question as possible.

[wahoo95]

Are you referring to chamber pressures? Using 223 for example Supersonic generates pressures greater than 50k psi, while Subsonic tends toto be 13k-20k psi