FLIGHT OF A BULLET

Manawatu Times, Volume XL, Issue 13211, 30 September 1915, Page 7

FLIGHT OF A BULLET

AN AEEI.4T, TOP

By the time a small bore bullet reaches the muzzle ot a gns. it is moving forward at the rate ot" over 2000 feet per second, and making 2400 revolutions in tho san,e time, the veloc-' ity giving it an energy cm about 1700, the rotation of about i-7 t :-lf\ together j forming an enormous fjTKiniiiy to concentrate in a smaL <• i» ji--1 weighing but a couple of hur. ir.-t grains. The rotational energy en '.bios the bullet to maintain its stability (says ■'Engineeringand thus indirectly contributes to its ranging pov>cr by compelling it to travel end on, and constantly offer a minimal .■•is'.au-jc to the air. Unfortunately, the wh >!" of the kinetic. energy of the .< i s. not transferred to the bullet, ' V 'he instant the latter leaves the muzzte there is a tremendous rush of g .r'j .<:■.< it. This ''muzzle blast'' is .1 '"'Ving thorn in the side of the 1 .'illistician, since, apart from the was -.> i energy, there •is a tendency for t; ;•<». g.»<es, with a higher muzzle veloc y than that of the bullet, to shove tV of the latter out of line an 'cmffr the bullet to topple over. L" '■ n so, fhis could not occur were it the fact that it is impossible \ nuke the muzzle of a rifle and tV. of a bullet so accurate tha i the ' leaves the former simultaneo- ; all points, and it is the inevitr -light asymetrical relationship be' - " n n these parts that causes the ini -it-ng which the muzzle blast accentuates. Elongated bullet* f.rod from a smooth bore are four :>e travelling side on at a distanc 1 '* two feet: in consequence of t- muzzle blast; hence the necessity i l rt ng bullets of a very rapid 'pin. However, despite this raoid sp' • '-e bullet still wobbles a little at v -tanning of its flight, a faet wh'"' 1 . throws light on the aggravated tra effects occasionally seen after range fir-

mg. A spinning top in at the commencement of spi 't f "falls asleep." and, bo far ' 1 ♦'".relation is concerned, becomes rr' >r!ess: finally, towards the end, it st- "jers about and rolls over. Now. a 1 i ;l ° n aerial top. spinning several times a second on a layer e - rsed air; like the toy counterp " '"bbles at first, then becomes • ■ '"d finally nt the end of long 1 when its rotary speed has co~ • .'>lv fallen,! it again becomes u r Tnis is J one of the explanati r ' " f ho aper- j tiire made in a pier "Wjis bv a; bullet is larger at t' ~>T<ing and j at the end of n lov *■ than the j aperture made at t-"" ••'"rmedinte point of flight. As the bullet leav : 1e it is quite a different tV what it i\as before til* 1 pull • -'nrger; its surface is polished by friction with the consequence of the r?»' r "mperature is raised. nnd if ' . n, l v stf>r ' j|p—tlmt is f o spv. r' n d spores previously lodged in 'cities of its surface liaye be- A ' lastly, it possesses moment'" in virtue both of its r- and its translation. b I cannot sing the o 1 " "ongs Which I should «' "?ht, I've lost my voice have no choice, Because "f bronel- -t; But very soon I'll v And sing them rl' •'O- - ckango my mo?<" Wt tones, Wit* Greet * nint Core.