CS: Target-info on in-the-ear hearing protection
From: Jonathan Spencer, [EMAIL PROTECTED] In an earlier post, I said: I have measured the sound pressure levels of all of these (the BP 'rifle' was a riot gun firing CS and plastic baton ammo) and the pressure curves of HV rifles exceed everything else. and [EMAIL PROTECTED] It wasn't so much the sound pressure level as the frequency curves. The Noisebreakers have a baffle system that lets some frequencies through better. Very high frequencies, like bird song, are hardly attenuated at all. It's my understanding that it is the high frequency noise that does the damage. I'm open to correction on this, as ever. I would be interested to see your results, if you have them online or electronic. Here are some figures. If anyone uses these, courtesy requires you to quote the source (Jonathan Spencer of Keith Borer Consultants). I don't have frequency of SPL the graphs we produced. (outdoor) (indoor)(indoor) 9mm SW 5946124.1 124.0 9mm GLOCK 17128.5 HK MP5 standing121.9 120.1 126.0 HK MP5 prone 122.4 126.0 SW .38 124.3 120.4 126.0 Rem 700 7.62 kneeling 124.8 AR 180 5.56127.1 L85A1 5.56129.7 FN 7.62mm 130.5 Rem 870 12ga buckshot 124.4 Rem 870 12ga slug 125.8 SW 100P 12ga 131.0 Schermuly 37mm 125.9 1ยป" L67 122.5 --Jonathan Spencer, firearms examiner ---[Cybershooters contacts] Editor: [EMAIL PROTECTED] Website subscription info: www.cybershooters.org
CS: Target-info on in-the-ear hearing protection
From: Jonathan Spencer, [EMAIL PROTECTED] Please note that they are fine for 7.62, 5.56 and .22 rimfire, but I haven't tried them with a high charge BP rifle yet, or shotgunning, so I don't know how good they are for that. If they are fine for high velocity rifle, then they are fine for shotguns and BP rifles. I have measured the sound pressure levels of all of these (the BP 'rifle' was a riot gun firing CS and plastic baton ammo) and the pressure curves of HV rifles exceed everything else. --Jonathan Spencer, firearms examiner "Necessity is the plea for every infringement of human freedom. It is the argument of tyrants; it is the creed of slaves." William Pitt, Earl of Chatham, speech 19 Nov 1783 "Where laws ends, tyranny begins." William Pitt, Earl of Chatham, speech 9 Jan 1770 [EMAIL PROTECTED] (preferred) [EMAIL PROTECTED] == Keith Borer Consultants, Mountjoy Research Centre, Durham, DH1 3UR, England tel: + 44 191 386 6107 fax: + 44 191 383 0686 visit our web site athttp://www.borer.demon.co.uk Lat. 54 34.24 N Long. 1 20.17 W == ---[Cybershooters contacts] Editor: [EMAIL PROTECTED] Website subscription info: www.cybershooters.org
