CHAPTER XV.
ON GUN BARRELS.
Long and Short Barrels.—A long barrel may be preferable for several reasons: 1st. A longer distance between the sights is given and the back sight can be put farther from the eye, so that finer sighting is possible; 2d. A long barrel is steadier in off-hand shooting; 3d. It permits a slower burning powder to be used, so that the charge starts more slowly and yet allows the full strength of the powder to be used before it leaves the barrel, getting a high initial velocity with but little recoil.
The short barrel has an advantage over the long one inasmuch as it can be handled with greater quickness and the sight can be brought to bear more readily, especially if the game be moving. If the barrel be long enough to give the charge the full benefit of the propelling power of the powder it may be deemed all sufficient. Yet, as to this, tastes and experience may so differ as to raise many conflicting opinions.
Except in some localities, as in case of districts where the old-fashioned Kentucky rifle is used, long barrels have been pretty much abandoned. A few years ago it was not uncommon to find barrels three and even four feet long, now the lengths will range from twenty-six to thirty-two inches. The length of the old Government musket barrel was originally forty inches, but has been lessened about seven inches. With the long barrels, a coarse, slower burning powder may be used and get a good result, but as a general thing cut off the barrel to a convenient length for off-hand shooting and moving game, use a finer-grained powder, which will be quicker burning and just as good results are obtained.
A gun having barrels over thirty inches in length, must needs be made with heavy barrels, and is very fatiguing to carry in an all day hunt. A gun of this kind, to be safe and well-proportioned, ought to weigh nine or ten pounds.
If fine and quick-burning powder be used in a long barrel, the powder is flashed into propelling gas, instantaneously, and beyond a certain length of barrel has no further expansive power, and the result is a friction of the charge in escaping, that affects the shot and consequently the pattern on the target. If slow burning powder be employed in a short barrel, the whole of the powder cannot be so instantly flashed into the propelling gas and some portion of it is, as a result, driven unconsumed from the muzzle of the gun.
This fact can be very readily ascertained by firing a gun over a bed of clean snow or over a spread of white cloth. The unconsumed grains can be readily seen on the white ground. If a less charge be used in order to consume all the powder, less velocity will be given to the projected charge, and weak shooting and a poor, scattering effect on the target is the consequence.
Proof of Barrels.—In consequence of the bursting of guns of an inferior quality, all barrels of English manufacture that are intended for home use, and also those designed for exportation, except a certain class of arms, are required by law to be proved and stamped with the proof-mark and also what is termed a view mark, which is a stamp or impress of the inspection after the barrels were grooved. There are two of these proofs called, respectively, the London and the Birmingham proof. In 1855, an Act was passed by the English Parliament, called, “The Gun Barrel Proof Act,” which enacted that all barrels should be proved, first, in the rough, and was called the provisional proof, and afterward when the barrels were put together, breeched and percussioned they were proved again, and this was called the definitive proof.
The arms to be proved are to be divided into classes, and the first class comprises single-barrelled military arms of smooth bore, and they are not qualified for proof until they are fitted and complete to be set up or assembled. The second class comprises double-barrelled military arms of smooth bore and rifled arms of every description, whether of one or more barrels, and constructed of plain or twisted iron. The fourth class comprises double-barrelled guns for firing small shot, and these are subject to the two proofs, provisional and definitive. For provisional proof, if of plain metal, the barrels are to be bored and ground to size, the vent hole drilled of a size not exceeding one-sixteenth of an inch diameter, and a vent enlarged to one-tenth disqualified it for proof. Notches in the plugs, instead of drilled vents, also disqualified them. If the arms are of twisted metal, they are to be fine bored and struck up, with proving plugs attached, and vents drilled the same as in plain barrels.
For definitive proof the barrels, either plain or twisted, must be finished ready for assembling, with break-offs and locks fitted. The top and bottom ribs have to be rough struck up, pipes, loops and stoppers on, and the proper breeches in. The same finished condition is required for rifles, but, in addition, the barrels must be rifled. The third class comprises single-barrelled shot guns, and for proving they are to be finished ready for assembling, with breeches in; and all barrels, with lumps for percussioning, are to be proved through the nipple hole. The fifth class comprises revolving and breech-loading arms of every description and system, and for revolving arms are to have the cylinders with the revolving action attached and complete. The barrels for breech-loaders are subject to provisional proof, according to the class to which they belong, and to definitive proof, when the breech-loading action is attached and complete.