Muzzle blast is just muzzle pressure, i.e. the pressure released to the atmosphere as the bullet leaves the bore. Higher pressure rounds with slower burning powders will maintain higher pressure inside the bore and have a louder muzzle blast. Shorter barrels will release that pressure to the atmosphere when the pressure is higher.

So just pick the round with the lowest maximum pressure and shoot it in the longest barrel reasonable for the task, and if you handload use the quickest burning powder suitable for the task. Veral Smith wrote about this, if you want the lowest muzzle blast in a handgun get a large bore and shoot a heavy bullet paired with a fast powder.


I have a sort of pet theory that bore diameter also changes the pitch, with smaller bores having a higher pitch than larger bores. Given same pressures folks notice that the .357 has a very loud crack! whereas the .44 Magnum is more of a hollow boom. They're still both "really loud" (scientific term) at full power but the pitch makes the former seem more painful to the ears. The .30 Carbine in those Ruger revolvers has a notoriously painful muzzle blast.

Again, just a pet theory so I don't know if bore diameter is really the culprit or not, but most people do notice a difference in the quality of the sound.



A generic example of fast vs. slow burning powders. The fast powder builds up a higher pressure than the slower powder but it drops more quickly so at the muzzle the slower powder has maintained a higher muzzle pressure than the faster powder.

[Linked Image from celnav.de]

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