From: "Jonathan M. Spencer" <Postmaster@borer.demon.co.uk>
Newsgroups: rec.guns
Subject: SAFETY/RIFLE/PISTOL actual sound pressure levels: measurement values 
	in dB
Date: 10 Jul 1996 11:37:16 -0400

A while ago I said:-

#>#Yes, Ylikoski in Finland took measurements 10cm (4") from the shooter's 
#>#left ear.  The SPL from 7.62 rifles was around 150-155dB.  Pistols were 
#>#not far behind. 

I have been asked (and could have predicted) ....

#>Do you have a reference? 

Yes (see below).  The data for SPLs of rifles etc is given on page 45 of
Ylikoski's work.  In summary:

9mm pistol, 10 shots, 
mean SPL 154dB, mean energy 115dB, mean duration 0.3ms

.22 rifle, 3 shots, 
mean SPL 132dB, mean energy 92dB, mean duration 0.06ms
[this agrees with measurements taken by _Machine Gun News_

7.62 NATO rifle, live ball ammo
mean SPL 155dB, mean energy 118dB, mean duration 0.3ms
[Ylikoski comments "rifles impulses (assault rifle 7.62) still had a
peak SPL of 154dB at distance of 4m to the side of the muzzle".]

7.62 NATO rifle, blank ammo (believe BFA fitted)
mean SPL 157dB, mean energy 120dB, mean duration 0.3ms

Other interesting numbers I've obtained from various sources including
the Ministry of Defence, Ylikoski and _Machine Gun News_ are:

Weapon                  SPL     SPL    energy  duration
                        dB     dB(A)     dB     ms
======                  ===    =====   ======  ======
1)  7.62 rifle, ball        155     154     118     0.3
2)  7.62 rifle, ball        154     n/k     n/k     n/k
    7.62 rifle, blank       157     n/k     120     0.3
3)  5.56 SA80 rifle, ball   161.5   n/k     n/k     n/k
4)  5.56 SA80 rifle, blank  149     n/k     n/k     n/k
5)  5.56 SA80 rifle, blank  158     n/k     n/k     n/k
6)  5.56 M16 rifle, ball    163     n/k     n/k     n/k
7)  5.56 M16 rifle, ball    132     n/k     n/k     n/k
8)  9mm Uzi SMG, ball       160     n/k     n/k     n/k
9)  9mm Beretta, pistol     161     n/k     n/k     n/k

notes:

1) 10cm from shooter's ear
2) 4m from muzzle at 90 degrees
3) 2m from muzzle at 90 degrees
4) Fitted with Blank Firing Adaptor; 2m from muzzle at 90 degrees
5) not Fitted with Blank Firing Adaptor; 2m from muzzle at 90 degrees
6) Without sound suppressor; 1m from muzzle at 90 degrees
7) With sound suppressor; 1m from muzzle at 90 degrees
8) When fitted with sound suppressor, 135dB
9) When fitted with sound suppressor, 135dB

OK, the reference for Ylikoski's paper(s) (which is a bound volume of
several papers, A5 sized, about 1/2" thick) is:

Matti Ylikoski,
Exposure to gunfire noise: some auditory and non-auditory consequences
associated with disability and handicap in army officers,
Kuopio University Publications, D. Medical Sciences No. 46,
Department of Otolaryngology, University of Kuopio, Finland, 1994
ISBN 951-780-426-1
ISSN 1235-0303

Distributed by:
Kuopio University Library, PO Box 1627, FIN-70211 KUOPIO, Finland. tel:
+358 71 163 430, fax: +358 71 163 410.

--Jonathan Spencer
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