RIFLE-BARREL STEEL, .30 CALIBER.
80
No. 7389.
Marks M 3 B.
Exterior diameter, ".466.
Interior diameter, ".300.
Sectional area, .10 square inch.
Gauged length 3."
From middle of length of finished barrel, rolled and annealed at residual heat.
Remarks.
Initial load.
Elastic limit.
Tensile strength.
Permanent set.	Successive permanent set.
Inch. 0. 0.	Inch. 0. 0.
	
	
	
	
0.	0.
	
	
	
	
	
	
	
	
	
	
	
	
	
Successive elongation per inch.
Elongation per inch.
Inch.
0.
.000100 .000200 .000333 .000367 .000333 .000334 .000333 . 000333 . 000367 .000333 .000134 .024833 .001333 .001167 .002933 .003933 .0094 .0166 .0300
Inch.
0.
.000100 .000300 .000633 .001000 .001333 .001667 . 002000 . 002333 .002700 .003033 .003167 . 028000 .029333 .030500 .033433 .037333 .0467 .0633 .0933
Applied loads per square inch.
Pounds. 1,000 5,000 10,000 20,000
30.000
40.000
50.000
60.000
70.000
80.000
90.000
93.000
94.000
95.000
96.000
98.000
100,000
105.000
110.000 115,000 117,400
.pounds.. 117,400
....do... 93,000
___inch.. .1800
....do... .003167
....do...	.106
..	95 from neck
silky, cup-shaped .. ". 27*, ". 16,	11
General summary.
Tensile strength per square inch of original section...
Elastic limit per square inch of original section......
Elongation per inch after rupture......................
Elongation per inch under strain at elastic limit......
Reduction in external diameter at point of rupture.....
Postion of rupture.....................................
Character of broken surface............................
Elongation of inch sections............................