191
BECOIL MECHANISM---15-POUNDER GUN NO. 12.
right trunnion the micrometer was attached to the trunnion at its center; on the left trunnion the micrometer was attached to the smaller projecting hub.
Diagrams 1 to 5 graphically show certain of the movements observed.
No. 10279.
Gun in Firing Position.
On gauged length A, from bottom of sleeve at rear end of lug to fixed block on gun.
Applied loads.	Gauge readings.		Remarks.
	Direct movement.	Set.	
Pounds.	Inch.	Inch.	
1.000	0.	0.	
3,000	.0010		
5,000	.0021	.0007	
7,000	.0034	.0008	
10,000	.0051	.0009	
12,000	.0064	.0009	
15,000	.0083	.0010	
17, 000	.0093	.0010	
20,000	.0112	.0010	
22,000	.0125	.0010	
25,000	.0141	.0010	
27,000	.0154	.0010	
30,000	.0172	.0011	
32,000	.0184		
35,000	.0202	.0011	
37,000	.0215		
40,000	.0235	.0011	
On gauged length B, over ends of piston rod:
1,000 5,000 10,000 20,000	0. .0006 .0022 .0041		
[Change in extremity of gauged length.]			
30.000 40.000 40.000	.0005 .0036 ». .0036	-.0070 -.0070 -.0070	
On gauged length C, from bottom of oscillating slide, front end of lug, to fixed block on gun:
1,000	0.	
10,000	.0038	
20,000	. 0093	
30,000	.0149	
40,000	. 0205	o.
On gauged length D (difference of A and C), from bottom of sleeve, rear end of lug, to front end of lug on oscillating slide:
1,000	0.		
10,000	.0002		
20,000	.0000		
30,000	-.0005		
40,000	-.0009	-.0001