778 The Shot-Gun. 



formed by "jumping" and hammering till the length of the barrel is 

 completed. 



Laminated steel barrels are formed of ribbons composed of six 

 parts of steel to four of iron, and the only difference between lamin- 

 ated steel and Damascus barrels is that the ribbons composing the 

 former are made of rods less twisted; but the ribbons are subjected 

 to more hammering when on the mandrel, in order to get greater 

 condensation and firm welding of the fibers of the two metals. 



The Proving of Gun-barrels. — The law in England requires 

 gun-barrels, whether of domestic or foreign make, to be subjected to 

 proof before they can be offered for sale when part of a gun. The 

 barrels are subjected to two proofs. The first is called provisional, 

 the second definitive proof. There are two companies in England 

 authorized by law to prove gun-barrels. The one at London is 

 called the London Gunmakers Company; the other, at Birmingham, 

 is the Birmingham Guardians. The tests are precisely the same at 

 both places. Barrels to be subjected to provisional proof are bored 

 and ground, and plugs are screwed into their breeches. In these 

 plugs the touch-hole is drilled. In the following table are given the 

 charges used in provisional and definitive proofs of the gauges of guns 

 given in the first column. I have added a column of usual loads for 

 these guns with which to compare the charges used in the proof-house : 



Gauge of j); am f oore WL of bullet or of Wi. of powder in pro- Wt. of powder in. defin- 

 gun. ' J ' shot in proofs. visional proof . M™ *,vnnf 



4 1.052 inch. 1649 S 1 " 5 - 9 2 8 grs- = 2 oz. 2 drs. 



8 .835 " 812 " 481 " = 1 " 1% " 



10 .775 " 641 " 372 " = 13^ " 



12 .729 " 535 " 353 " = 12^ " 



16 .662 " 399 " 295 " = i°J£ " 



Over the charge of powder used in either proof is rammed a cork 

 wad. Over this is placed the bullet, which is also covered with a cork 

 wad. In testing choke-bored barrels, the bullet is replaced by the 

 same weight of shot of No. 6, English. In the definitive proof, the 

 barrels have to be presented to the company in a finished state and 

 attached to their breech-loading actions. It is prohibited by law to 

 reduce the weight of these barrels, after the company has stamped 

 them to show that they have received the provisional and definitive 

 proofs. The stamps used by the London Gunmakers Company on 

 stM<u?\^ ,2B Mn T mr. = .. choke-bore barrels is as follows: 12 B x 



^(tfj^vif!^ M N0T F0R BALL 



'* M 14 M stand respectively for twelve gauge 



at breech, fourteen gauge at muzzle. 



* Single-barrel ducking-gun of 20 pounds weight. 



