Chamber pressure and noise

[Fremmer]

Is there a correlation between the amount of chamber pressure generated by a particular round, and the amount of sound perceived when the gun is fired?

I was thinking specifically of rifle rounds. Some of the high velocity 20 caliber hunting rounds sound pretty loud when you shoot 'em. Does the amount of chamber pressure produced by a round have anything to do with the decibel produced when fired?

[bcrash15]

I would think it would have more to do with the pressure at the time when the bullet leaves the barrel. Of course, all other things being equal (bullet, barrel diameter, length, type of powder, etc), a round with higher chamber pressure is going to have a higher muzzle pressure (not sure if that is an actual term, just made it up). Of course, IIRC, the nitro express rounds are relatively low chamber pressures, but I bet they are pretty darn loud. Because all those things mentioned above change between guns/calibers there are a lot of variables to be considered.

[Slopemeno]

Exactly right. Compare the noise of a 7MM mag and a 12 gauge shotgun, then go look at the pressure figures.

[Gewehr98]

Compare the sound pressure levels of the 7mm Remington Magnum, 12 gauge shotgun, and blackpowder-loaded .45-70 Sharps rifle. Crack - Bang - Boom. :D

[Scorch]

Does the amount of chamber pressure produced by a round have anything to do with the decibel produced when fired?
The pressure differential between the atmospheric pressure and the pressure in the barrel is what causes the report when a gun is fired. The expanding gases collide with the stationary atmosphere and make the gun go BANG. If the pressure were equal, there would be no report.