THE EOYAL ARTILLEEY INSTITUTION. 
135 
(3) screw-gauge fuze-hole, (4) plain plug to test pitch of fuze-hole, 
(5) recess-gauge fuze-hole, (6) high ring-gauge body, (7) low ring-gauge 
body, (8) high ring-gauge studs, (9) low ring-gauge studs, (10) cylinder 
gauge. 
Limits {stud 
± -01 in. 
± -005 in. 
Finally, the shell is stamped and painted. Upon the body of the shell are 
stamped the letters R.L. and the also the numeral. These marks will be 
found above one of the front studs in all calibres above the 64-pr., inclusive; 
in 40-pr. and downwards, below one of the front studs. On a rear stud is 
stamped the month and year of manufacture, and upon 7-in. and upwards 
a x, to indicate that the studs have been planed as well as turned. 
SHRAPNEL SHELL EOR THE 9-pe. R.M.L. GUN. 
The exterior of the shell is made in two parts:— 
1. The body. 
2. The head. 
The method of casting the body is similar in most respects to that given 
for common shell. The details of making the mould and core for body are 
the same, except that as the body consists of a cylinder open at top and 
closed only at bottom, the top of the core is so formed as to fit without 
leaving any space between it and the top of mould. At the bottom the core 
contracts, so as to form a powder-chamber; and has six projecting ribs 
which form grooves on the interior of the powder-chamber only.* The 
interior of the body is slightly conical, tapering off gradually from the 
powder-chamber to the top. 
The shell undergoes the same processes of knocking out and trimming as 
the common shell, but is not lacquered. The shell is then centred from 
inside and the body rough-turned in a lathe. A recess is next turned down 
on the upper part of the exterior of the body, over which the head fits ;t the 
body is then fine-turned. The operations for studding are next carried out 
in the same way as given for common shell.f The shell is gauged for thick- 
* The ribs are continued along the body of the core in all other calibres, to facilitate opening the 
shell, tapering as they approach the top, except the 16-pr., in which the grooves are dispensed with 
altogether. 
f The recess in the 7, 9, and 16-prs. is not so deep as formerly, as the rim of cast-iron was 
weakened and broke off. The rim has been thickened, the metal of the head being turned down to 
a corresponding amount at the junction. 
X In till calibres—9-pr. excepted—care must be taken to keep the stud holes, as far as possible, 
clear of the lines of least resistance. 
The shell is tapped with a hammer, to ascertain whether it has been cracked by the pressure 
applied in attaching the studs. 
