While doing some research on gunshot "loudness" I came across some interesting information I thought I'd share here.

I've always assumed that shotgun is louder than pistol; however, I quickly discovered it's quite the opposite. An 18" 12 gauge produces 156dB, compared to a 9mm, which rings in at nearly 160dB. A few more typical calibers:

.32 ACP 153.5 dB
.380 157.7 dB
.38 Spl 156.3 dB
.357 Mag 164.3 dB
.45 ACP 157.0 dB

.223, 55GR. Commercial load 18" barrel 155.5dB
.30-30 in 20" barrel 156.0dB
7mm Magnum in 20" barrel 157.5dB
.308 in 24" barrel 156.2dB

26" barrel shotgun 150.25dB

Source: http://www.freehearingtest.com/hia_gunfirenoise.shtml)

The pain threshold is at 120dB. OSHA Required Hearing Protection in Factory is 85dB. Sustained Exposure May Cause Hearing Loss is 90dB. A few more for good measure:

Chest Wall Begins to Vibrate 150dB
Ear Drum Breaks Instantly 160dB
Death of Hearing Tissue 180dB
Loudest Possible Sound 194dB

Some other interesting comparison: http://www.esoundproof.com/Screens/B...s/dBChart.aspx (this site lists shotguns at 120dB).

Muzzle brakes and ports INCREASE the dB level as the sound blast is closer to the shooter.

Consider how we are prepared to use all types of guns and ammo indoor for HD, short of wearing ear protections, hearing loss and disorientation caused by discharged gunshots indoor is a factor we should be aware of.

Al