Upload
hoangxuyen
View
231
Download
1
Embed Size (px)
Citation preview
GAU-19/A Barrel Life StudyJames St. Germain
40th Annual NDIA Armament Systems GDARM ConferenceNew Orleans, Louisiana April 2005
22
GAU-19/A Barrel Life StudyAgenda
GAU-19/A DescriptionBarrel Design ParametersCustomer BackgroundBarrels Used in the StudyBarrel Inspection & ResultsBarrel Testing & ResultsConclusion
40th Annual NDIA Armament Systems GDARM ConferenceNew Orleans, Louisiana April 2005
33
GAU-19/A Barrel Life StudyGAU-19/A Description
Three-barrel 12.7mm externally powered Gatling gunProvides lightweight, lethal firepower to a variety of platforms:
HelicoptersGround vehiclesNaval vesselsHigh speed patrol boatsFixed Wing Aircraft
40th Annual NDIA Armament Systems GDARM ConferenceNew Orleans, Louisiana April 2005
44
GAU-19/A Barrel Life StudyGAU-19/A Description
40th Annual NDIA Armament Systems GDARM ConferenceNew Orleans, Louisiana April 2005
55
GAU-19/A Barrel Life StudyGAU-19/A Description•Rate of Fire 1000/2000 spm (1,300 spm HMMWV)•Effective Range 1800 Meters•Maximum Range 6000 Meters•Max Dispersion 5 mrads (80 % circle) = 5m at 1000m•Weight 138 Lbs (gun & feeder assembly)•Reliability 40,000 MRBF•Average Recoil 600 Lbs at 2000 SPM•Maintenance 30,000 rds.•Barrel replacement 50,000 rds. per set•Sighting Holographic, NVG compatible, Laser Pointer•Uses entire range of .50 cal NATO / Mil Spec ammunition
40th Annual NDIA Armament Systems GDARM ConferenceNew Orleans, Louisiana April 2005
66
GAU-19/A Barrel Life StudyInitial Barrel Design Parameters
Crack Propagation Program utilized for barrel analysisEach barrel set must be capable of firing out a complete ammunition container loadTarget life expectancy of 35000 rounds per set used in analysis program
40th Annual NDIA Armament Systems GDARM ConferenceNew Orleans, Louisiana April 2005
77
GAU-19/A Barrel Life StudyBarrel Physical Description
Mat’l: CrMoV steel per A10505Bore: Chrome plated per A10374Exterior Finish: Solid Film Lubricant 119A211512.69 mm bore/12.98 mm groove diameter8 land rifling: right-hand constant twist 1 turn in 30 calibers
40th Annual NDIA Armament Systems GDARM ConferenceNew Orleans, Louisiana April 2005
88
GAU-19/A Barrel Life StudyCustomer Background
40th Annual NDIA Armament Systems GDARM ConferenceNew Orleans, Louisiana April 2005
99
GAU-19/A Barrel Life StudyBarrels Used in Study
Barrel sets from customers with 35,000 to 54,000 roundsTypical firing cycles of 50 to 100 roundsAPI ammunition
Barrel set from GDATP with 50,000 roundsTen 800 round bursts with all others at 200 to 400 roundsM33 Ball and M17 Tracer, 4:1
40th Annual NDIA Armament Systems GDARM ConferenceNew Orleans, Louisiana April 2005
1010
GAU-19/A Barrel Life StudyParameters Measured
InspectionErosion
Indicator of velocity reductionCrack Depth
Indicator of rounds to failureTest
VelocityIndicator of barrel performance and resultant targeting
40th Annual NDIA Armament Systems GDARM ConferenceNew Orleans, Louisiana April 2005
1111
GAU-19/A Barrel Life StudyParameters Measured – Barrel Erosion
Barrel Serial#1000003 50,000-rds. per set
Washout area from 800-rds. fireout bursts. More severe than other two barrel samples that were used by customer in combat and practice.
40th Annual NDIA Armament Systems GDARM ConferenceNew Orleans, Louisiana April 2005
1212
GAU-19/A Barrel Life StudyParameters Measured – Barrel Erosion
Bore Erosion .50 cal barrels
0.010
0.015
0.020
0.025
0.030
0.035
0.040
0.045
0.050
0.055
0.060
1.0
5.0
10.0
20.0
25.0
26.0
27.0
28.0
29.0
30.0
30.5
31.0
31.3
31.5
31.8
32.0
Distance from muzzle (in)
Gag
e re
adin
g
54 k Roundsper set
48 k Roundsper set
43 k Roundsper set
35 k Roundsper set
40th Annual NDIA Armament Systems GDARM ConferenceNew Orleans, Louisiana April 2005
1313
GAU-19/A Barrel Life StudyParameters Measured – Crack Propagation
1000273 53000-rds per cluster Cut plane @ 4.4 “ Crack depth .020 “
40th Annual NDIA Armament Systems GDARM ConferenceNew Orleans, Louisiana April 2005
1414
GAU-19/A Barrel Life StudyParameters Measured – Crack Propagation
.50 Cal. Barrel Life Analysis
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
0 20000 40000 60000 80000 100000 120000 140000
Rounds fired per barrel set
Cra
ck d
epth
(inc
hes)
Barrel 3 .0118 init crackColumbian barrel .006 intial crackLil Bird barrel .004 initial crack
40th Annual NDIA Armament Systems GDARM ConferenceNew Orleans, Louisiana April 2005
1515
GAU-19/A Barrel Life StudyParameters Measured - Velocity
Yaw present, tracer only
215054000
Yaw present, tracer only
221053000
Two minor yaws, tracer only
256548405
No yaw265545200
No yaw268043250
No yaw28004000
YAW RESULTSVELOCITY(ft./sec.)
ROUNDS AS RECEIVED
(per barrel cluster)
40th Annual NDIA Armament Systems GDARM ConferenceNew Orleans, Louisiana April 2005
1616
GAU-19/A Barrel Life StudyConclusion
At approximately 50,000 roundsSignificant velocity changeYawing begins to occur in tracers affecting targetingNo danger of crack propagation causing failure
BARREL REPLACEMENT PER ROUNDS FIRED CAN BE INCREASED FROM 35000 TO 50000 ROUNDS PER SET