Dec. 3, 1893.] 



FOREST AND STREAM. 



471 



test between their own articles and those of their com- 

 petitors. But that distrust has long ago given way to a 

 better sense of understanding. The conviction now pre- 

 vails that the work of these institutions not only benefits 

 the gunners at large, but also the well-meaning manufac- 

 turers and dealers, and that they afford .specially to the 

 home industry a great assistance and help. It may be 

 presumed tliat in this country also such an institution 

 will not suit the taste of some interested yjarties, although 

 an attitude of this kind would hardly conform to the gen- 

 eral principle of American enterprise, for which it is 

 claimed that our manufacturers willingly follow the 

 progress of tlieir industry. The g-unners, however, can, 

 if they follow the example set by their fellow sportsmen 

 of the old countries, easily overcome all such unwarranted 

 opposition or jealousy, inasmuch as they will simply 

 patronize and bestow their confidence on such manufac- 

 turers and dealers as do not £ear or hesitate to see their 

 products subjected to a fair and honest comparison with 

 other similar articles of manufacture. 



The encouragement I received at the hands of numerous 

 gunners from all over the country in respect to my inten- 

 tion to establish in this country an institution of the kind 

 alluded to, makes it appear pretty certain that such an 

 institution will meet with a great deal of cooperation and 

 assistance at the hands of the intelligent and wideawake 

 American sportsmen. 



Following m^ request, numerous suggestions have been 

 offered by gunners as to how the powder test should be 

 conducted. As far as these suggestions touch a general 

 interest, they have been taken into consideration. I have 

 thus been obUged to dwell in my report on questions not 

 in direct relation to these tests, and to give my report 

 somewhat the character of a treatise on the theory of shot- 

 shooting. 



The Bursting Strain in Gun Barrels. 



The combustion of nearly all gun powders takes place 

 under different conditions in a confined space from those 

 in the open air. In the open air most of the nitro powders 

 burn comparatively slowly, and, contrary to black pow- 

 der, without explosion. On this account! the handling of 

 nitro powders is not as dangerous as that of black powder. 

 As much as SOOlbs. of gun cotton powder can be bmned 

 in the open air without creating thereby any serious dan- 

 ger for the surroundings. But when powders are brouglit 

 to combustion in a confined space, their behavior under- 

 goes quite a change. The nature of ignition plays in this 

 case a very important part. 



When a cliarge of powder is exploded in the gim bar- 

 rel, the stored potential energy is transformed into live 

 force. The developed, strongly condensed gases occupy 

 about 230 times the sp.ace of the volume of the original 

 powder charge, and, in consequence, a strong tension is 

 created, first, in and near tlie powder chamber, and then 

 along a certain portion of the gun barrel; this is termed 

 bursting strain, or gas pressure, and imparts to the pro- 

 jectile, and in the shotgun to the shot charge, the ijropel- 

 ling force. The more space afforded to these gases to 

 spread in a gun barrel, the less the strain will be at a 

 given point, and on the other hand this tension will in- 

 crease if its spreading is for some cause made difficult, or 

 if confined to a small space. For this reason the tension 

 will always be comparatively low with such powders as 

 generate their gases more slowly and gradually than with 

 a powder which burns more suddenly, and which devel- 

 ops the great bulk of its gases before the shot charge has 

 found time to move much toward the muzzle and create 

 a larger space for the expanding gases. 



The modern blasting agents develop, as a rule, their 

 gases so suddenly that on this account they cannot be 

 employed as propelling agents. Such a sudden comljus- 

 tion and development of the gases is called a detonation. 

 Every guni)uwder, the black powder not excepted, can, 

 through the agency of a highly violent yjrimer and for 

 other causes, be brought to a very sudden ignition or 

 combustion, although the black powder will, in this res- 

 pect, resist many ordinary causes more effectually than 

 the nitro powders. But this sudden combustion hardly 

 ever assumes the natm-e of a real detonation, yet it may 

 resemble the latter so closely that, especially with a 

 powder susceptible to dry heat, it no longer conforms to 

 the limits of safety for the gun and gunner. 



The perceptible signs of such sudden conbustions are 

 generally an extraordtnai-ily heavy recoil, producing fre- 

 quentl}' a ringing in the gunner's ear, a marked vibration 

 of the gun and a bad pattern, sometimes coupled with a 

 balling of the shot. 



As long as the gunner uses a well built, sti'ong gun, he 

 is seldom exposed to any real danger, although, in some 

 instances, the action of the gun is more or less damaged. 

 But the case is quite different if such a shot happens to 

 occur in a cheap, less substantially made gun, which, 

 as a rule, does not possess sufficient strength to withstand 

 such a liigh pressure. Here the locking device will likely 

 fail to answer its purpose, or the barrel may bulge or 

 burst. Even with powders not affected by dry heat, such 

 a result can be brought about merely through the agency 

 of a violent primer. 



Nitro powders, as a rule, will not stand an increase of 

 the charge beyond the standard load as readily as black 

 powders, but in spite of these facts, many shooters will 

 not draw correct conclusions from them. They seem to 

 believe that the strength of penetration will grow with 

 the increase of the powder charge, and do not conceive 

 that such is not the case, that they frequently achieve 

 just the contrary from what they are striving at, and that 

 they create a source of eminent danger. 



In a subsequent chapter it will be demonstrated that 

 many American gunners are in this respect guilty of 

 gross carelessness, and ill-informed. They simply indulge 

 in the luxury of wasting powder and shot. 



The loads of nearly all nitro powders are measured with 

 .the dip-measure, which affords ample accuracy. Three 

 drams by measure repres'^nt, according to the specific 

 weight of the different powders, from 38 to 41grs. by 

 weight? equal to 3 65 to 2.13 grams. Tiie corresponding 

 charges of Walsrode powder are smaller by weight and 

 in bulk, they are for 12-bore guns, 29 and 31, or 31 and 

 32gr.^. 



All propelling agents develop iji summer, and especially 

 in warm and dry weather, a higher bursting strain than 

 in winter in a low' temperature or moist atmosphere, and 

 fine shot again creates, owing to the larger surface of 

 friction, a higher gas pressure than the coarse or larger 

 pellets, and the bm-sting strain of l^oz. is less than with 

 J^z, of the same size shot, 



In America much shooting is done in summer and dur- 

 ing warm weather. A great number of our celebrated 

 shots prefer to load for 12-bore ammunition Sidrs., in- 

 stead of the normal charge of 3drs., or of Walsrode 

 powder Slgrs. in place of 29grs.; forgetting that these 

 maximum charges are only suited and intended for cold 

 or wet weather. 



As a rule the pattern is always less satisfactory from 

 the large load than from the service charge, and in some 

 cases where powders susceptible to dry heat are used, the 

 chances of a balling of the shot are materially increased 

 by the heavier load. 



The quantity of powder loaded in excess of the standard 

 charge is therefore uselessly Avasted, and the same rule 

 applies generally, as wdl be subsequently shown, to an in- 

 ci'ease of the shot charge beyond l|oz. 



The gas pressure in a shotgun reaches the highest point 

 in the cartridge chamber and immediately in front of the 

 same in the direction toward the muzzle. 



Black powder, as a rule, produces at this point less gas 

 pressure than the nitros, but a somewhat higher bursting 

 straui in the middle and up to the muzzle than the latter. 

 It has been stated, previously, that the bursting strain, 

 especially when smokeless powders are used, is influenced 

 by several causes. The soft, elastic felt wad diminishes 

 the gas pressure compared with the felt or any other hard 

 wadding material, and also diminishes the chances for a 

 balling of the shot, which occurs much less frequently in 

 Europe than in America, probably on account of the 

 more moderate mean temperature' and the higher per- 

 centage of humidity in the air prevailing there, compared 

 with a large part of this country. 



The true causes for the balling of shot have thus far 

 not been satisfactorily established. Some advance the 

 theory that owing to an exceptionally sudden combus- 

 tion of the powder, the temperature in the cartiidge is 

 raised to a point of fusing a portion of the shot. But 

 since the wad has its place laetween the powder and shot, 

 the effects of such a high heat would naturally leave its 

 traces also on the felt wad. The heated gases passing the 

 edges of the wad to fuse the shot would necessarily char 

 these edges more or less. 



In the course of the experiments at Chicago, in a com- 

 paratively large number of cases, the shot balled, and these 

 were nearly all cartridges loaded with more than 3drs. 

 fo nitro powder; but no charred or singed wad was 

 found. 



Again, others hold that the balling of shot is brought 

 about by a friction of the shot differing from the normal 

 conditions whereby the cohesive quality of the pellets is 

 increased to such an extent that they cling together in 

 lumps of greater or smaller dimensions. This theory like- 

 wise is not unimpeachable. 



In my opinion, which is shared by many others, it ap- 

 peal's more probable that in consequence of the sudden 

 generation of the gases of a large powder chai-ge and the 

 high tension thus created in the shell, the energy devel- 

 oped ceases to exercise its forces in a gradually shoving 

 manner, but more in the shape of a heavy blow, thereby 

 causing a portion of the shot to press together. Such a 

 heavy blow apparently is too sti'ong for the wad to retain 

 its quality as a buffer. As a matter of fact, the balling of 

 shot occurs more frequently with hard wads than with 

 soft and elastic ones; and this presumably for the reason 

 that a soft wad more effectually deadens the force of the 

 blow tlian a harder material. It was further proved in 

 Chicago that the tendency of balling was less with harder 

 shot than with softer, and less with pellets of a more 

 even spherical shape than with those less regular in form. 

 The balling of the shot occurs more frequently in the open 

 barrels than in the chokebore. The cause for this may be 

 due to the effect of the passage of the shot through the 

 choke, whereby the bunches formed are again torn apart. 

 If this theory is correct, the next question would be, 

 why, in such a case, the choke should not show traces of 

 bulging, since a hard and stiff top wad often suffices to 

 bulge the barrel at the point of the choke in soft Damas- 

 cus laarrels. 



Twelve-bore guns are generally chambered for 2| and 

 2ri shells. Some gvms are chambered for 3in. shells. In 

 guns chambered for 2^ shells, 2| shells can be us^d with 

 about the same result as the longer ones, provided the 

 proper wadding material is employed. In all such cases 

 the felt wad should be somewhat larger in diameter than 

 the bore of the barrel. An elastic wad 11-gauge will 

 then be most suitable for a 12-bore barrel, in order to 

 prevent the gases from passing the wad at the point 

 between the end of the shell and the end of the chamber. 

 The 2-J shells, however, should not he used in a gun cham- 

 bered for 2| shells, and a shell Sin. long will, in such a 

 case, present a serious element of danger. If the 3in. 

 shell is crimped strongly it can be squeezed mto a 2| 

 chamber, but when fired in such a chamber the crimped 

 part cannot open and conform to the shape of the cham- 

 ber in the regular manner. An artificial obstruction is 

 thus created which prevents a normal expansion of gases 

 and, as the Chicago tests have proven, is likely to cause 

 a bursting strain in the chamber higher than the average 

 gun can safely bear. 



At the point where the cartridge chamber ends, and the 

 so-called "soul" of the barrel commences, there shoudd 

 never be a perceptible shoulder; that point should be of a 

 conical or tapering shape and ought not to be of great 

 length. The latest American guns, as a rule, are in this 

 respect made in strict accordance with what experience 

 and science have proven to be the safest and most advan- 

 tageous style, so are also the Francotte and other imported 

 guns. 



Wads made of cork or other materials less elastic than 

 felt should never be used in connection with nitro pow- 

 ders, for the reason that they may give occasion for ex- 

 traordinarily high gas pressure, and on similar groimds 

 the use of brass shells is not advisable. 



In order to achieve a thorough combustion of the nitro 

 powders, the shells should be crimped at least iin. The 

 strong crimp also serves to prevent the shell loaded in the 

 left barrel from opening through the eft'ects of the shots 

 fired from the right barrel, or vice versa. But even if the 

 shells are crimped well, it shows good judgment on the 

 pai-t of the gunner, if he, after firing several shots from 

 one barrel, examines the cartridge loaded in the other bar- 

 rel, or takes out the latter and loads it in the barrel for 

 the next shot. 



If the crimp of the shell becomes loose and the shot 

 charge happens to move up a shorter or longer distance 

 in the barrel and such a shell is fired, a bulge or burst 

 piay be the consequence, the effect being'about the same 



as in the case when the muzzle of the barrel is filled with 

 dirt or snow. 



Shells made of very stiff pajjer should not be turned 

 down more than ^in., and fur such shells the round crimp 

 is preferable to the square-edge crimp. 



Pieces torn from a shell and deposited in the soul of the 

 barrel ought to be considered an element of danger, inas- 

 much as they may serve as an artificial obstruction. If a 

 fired shell shows traces of damage, or when other strange 

 signs accompany a shot, the gunner should in all such 

 cases ascertain whether his gun barrel is free of all ob- 

 structions before he continues to fire. 



The question as to how much bursting strain a shotgun 

 will safely stand has been put to me by numerous parties. 

 This question can hardly be answered in a general way, 

 since the gas pressure still comparatively safe for one gun 

 may prove hazardous for another less substantially built 

 gun. It may, however, be assumed that all shotguns 

 placed in the hands of a gunner should be strong enough 

 to withstand the bursting strain developed by a proof- 

 house charge of powder and shot for finished guns. 



The proof -house charge for finished guns, as prescribed 

 by law in several European countries, for the testing of 

 finished guns, is equal to about 7dr3. black powder and 

 Ifoz. of shot. In order to determine what gas pressure 

 such a load would give in this country, and to establish a 

 standard of comparison for all nitro powders in reference 

 to bursting strain, e^drs. of DuPont's FFF black pow- 

 der, which appears to develop, bulk for bulk, a greater 

 gas pressure than the European blacK powders, and l^oz. 

 shot, No. 7, were loaded into the gas-pressure gun at Chi- 

 cago, and fired. This load developed a bursting strain of 

 1,100 atmospheres or 16,1701bs. to the square inch. Very 

 few guns would prove sti'ong enough to withstand such a 

 strain for any length of time. 



About 75 per cent, of the figures quoted is as much as 

 the ordinary shotgun ought to be subjected to. The limit 

 for shotguns is much lower than that drawn- for the 

 modern small-bore mihtary rifles, which will stand a gas 

 pressure as high as 3,500 atmospheres, or from 35,000 to 

 40,0001bs. 



For measuring the bursting stram, a Hahn's pressure 

 gauge for 12-bore was employed at Claicago and Carney's 

 Point, and this caliber forms' the basis for all experiments 

 herein referred to. 



The consti-uction of this instrument, which at the 

 present time is recognized as the most improved and re- 

 liable, differs from all the old similar apparatuses, inas- 

 much as with it the bm-sting strain can be taken simul- 

 taneously or separately on the old crusher gauge princi- 

 ple and by means of a spring device. 



The bursting strain figures quoted herein were all 

 determined with the spring device. The double spring 

 taking the place of the metal cyhnder on the crusher 

 gauge is actuated by a piston plunger, reaching into the 

 interior of the barrel and there conforming accurately to 

 the side of the bore. 



When the gases press against this piston, the latter acts 

 on the spring, pressing it together. A pin reaching to 

 the spring next to the barrel and resting there is driven 

 outward in proportion to the degree the spring is pressed 

 together, and this pin travels through a graduated screw 

 disk, thus registering the extent of the contraction of the 

 spring, or, in other words, enabhng the operator, by 

 means of the graduated disk, to read off the gas pressure 

 in plain figures. 



This spring is much more sensitive to low as well as to 

 high gas pressure, than the metal cylinder, which, when 

 pressed down to beyond a certain depth, wiU, owing to 

 the increased dens'ty of the metal, offer much more re- 

 sistance proportionately than it did in its original length 

 and shape. Consequmtly the spring device, as a rule, 

 furnishes somewhat higher figures than those obtained 

 under similar conditions with the crusher gauge, but the 

 figures secured with the former may be ccnsidered nearer 

 the truth than those obtained with the latter. This ex- 

 planation appears to be called for, since in its absence, 

 a.nd when the figures herein given are compared with 

 those obtained with the crusher gauge, the former might 

 be looked upon as far too great and therefore unreliable. 



The fact that the gas pressure values as obtained at Chi- 

 cago and Carney's Point seem rather high when compared 

 with similai- figures taken from the same powder charge 

 in Europe, can hardl / be accounted for simply by the dif- 

 ference in the instruments employed. There can be no 

 doubt that these variations are, to a gre;.t extent, due to 

 the difference in climate. It is certain that the majority 

 of propelling agents will, when loaded bulk for bulk, de- 

 velop a higher bursting strain in this country than in 

 Europe, where the mean temperature is below that of 

 America and the air less dry than in a great portion of 

 the United States. 



The gas pressure gauge plays in ballistic experiments a 

 very important part. It is of great value and help to all 

 gun and ammunition manufacturers, and indispensable 

 for powder manufacturers. 



In the absence of such an instrument, the ballistic 

 properties of a powder, especially with reference to 

 its degree of violence, can never be satisfactorily estab- 

 lished, and, again, the causes for increased bursting 

 strain in gun barrels can only be determined with the aid 

 of such an instrument. 



Velocities and the Method of Ascertaining Tlnem. 



The term velocity applied in a general way designates 

 the rate of speed at which a projectile or the bulk of a 

 shot charge travels through the air up to a certain point. 



This velocity can be ascertained by various methods, but 

 the instrument now generally employed is the chrono- 

 graph Le Boulenge, originally invented by a Belgian mili- 

 tary officer bearing that name. The application of this 

 instrument is as follows: When a bullet or shot charge 

 leaves the muzzle of the gun, it is obliged to cut a fine 

 silver or copper wire stretched across the muzzle. This 

 wire conveys a current to an electro-magnet on the upper 

 partot the instrument to which a cyHndrical roJ, covered 

 with a zinc sheatli, is perpendicularly suspended and held 

 by the attraction of the electro-magnet. This rod, which 

 is called the chronometer, drops immediately the wire be- 

 fore-mentioned is broken and the current opened. The 

 target is connected by wire with a second electro-magnet 

 on°a lower part of the chronograph, wherein a second 

 current is created. To this second electro-m agnet a shorter 

 rod is similarly suspended ca lled the registrar, which drops 

 as soon as the perpendicularly suspended and sliding tar- 

 get is moved from its contacts and the current thereby in- 

 terrupted. The shot charge having cut the yfh^ stretched. 



