OSS Helix 5.56 Testing

	A	B	C	D	E	F	G
1		Middle GA			Weather:	Start:	End:
2	Date:	07/26/2019			Temp (°F)	84.6	N/A
3	Time:	2:55-3:12PM			Humidity	48%	N/A
4	Elevation:	736 ft			Pressure (Hg)	29.39	N/A
5					Wind:	0.0 @ 21°	N/A
6					Density Altitude	2550ft	N/A
7
8	18" BCM Build Superlative Piston (Restrictive Mode)				Unsuppressed
9	GGG 62gr M855 Ball				Muzzle		Right Ear
10					166.8		157.2
11	Silencer	Muzzle	NSR	FRP	Right Ear	NSR	FRP
12	OSS Helix 5.56	140.4	26.4	2.0	138.2	19.0	-1.3
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15	Location	Middle GA			Weather:	Start:	End:
16	Date:	04/23/2019			Temp (°F)	85.4	N/A
17	Time:	4:04-4:15PM			Humidity	40%	N/A
18	Elevation:	753 ft			Pressure (Hg)	29.3	N/A
19					Wind:	2.8mph @ 225°	N/A
20					Density Altitude	2617ft	N/A
21
22	12.5" H&M Defense Monobloc Mid Length Upper				Unsuppressed
23	GGG 62gr M855 Ball				Muzzle		Right Ear
24					167.4		160.3
25	Silencer	Muzzle	NSR	FRP	Right Ear	NSR	FRP
26	OSS Helix 5.56	143.1	24.3	1.0	148.1	12.2	-1.9
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28	NSR = Net Sound Reduction
29	FRP = First Round Pop
30	SPL = Sound Pressure Level
31	OBA = Octave Band Analyzer
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33	All official testing conducted per MIL-STD 1474 D specifications using a Bruel & Kjaer 2209, A-weighted
34	Open area/field with no sound reflective surface within 10m of 4136 pressure mic
35	Muzzle measurements 1.6m high, 1m left of exit aperture
36	Right ear measurements taken 30cm from front of ejection port, 8cm high and 15cm right of bore centerline
37	Frequency Analysis Data collected using Larson Davis LxT Octave Band Analyzer, Normal Range, A-Weighted, single shot with two second total meter runtime
38	OBA curve charted to match average SPL from 2209 at each metering postition, provides visual representation of the tonal signature of silencers/moderators tested
39	Meters calibrated prior to and after testing using a Larson Davis CAL-200 at 94dB & 114dB with <.05dB variance
40	Weather data collected using WeatherFlow meter & GeoBallistics on-site
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