The morning call., 1893-12-10

of the gun barrel; this is termed bursting
strain, or gas pressure. and imparts to the
projectile, and in the shotgun 10 the shot
charge. the prOpelling force. The more
space afforded to these gases in a gun
barrel, the less the strain will be at a
given point, and, on the other hand, this
tension will increase If its spreading is for
some cause made difficult, or If confined to
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
developes 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 rule, their gases so suddenly that on
this account they cannot be employed as
propelling agents. Such sudden COM
bustion and development of the gases is
called a detonation. Every eunpowder.
the black powder not excepted, can,
through the agency of a highly violent
primer and from other causes. be brought
to a very sudden ignition or combustion,
although the black powder WILL in this re-
spect, resist many ordinary causes more
effectually thar the nitro powders. But
this sudden mbustion hardly ever
assumes the nature of real detonation,
y
that. especially with powder susce pt BILE
to dry heat. it no longer conforms to the
limits OF safety for the gun and gunner.
The percep tible signs OF such sudden
combustlODs are generally an extraor-
dinarly heavy recoil. producing fire.
quently ringing in the gunner's ear, a
marked vibration of the gun and bad
pattern, sometimes coupled with balling
ofthe shot.
AS long as the gunner uses well-built,
strong gun, ne is seldom exposed TO any
real danger. although. in some instances,
the action Of the gun is more or less dam
aged. But the case is quite different If
such snot happens TO occur IN cheap,
less substantially Dade gun. which. as a
rule, does not possess sufficient strength
TO withstand sucn n high pressure. Here
the locking device will likely fail to an
swer 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 vio-
lent primer.
Nitro powders. as 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 no,
conceive that such is not the case, but they
frequently achieve just the contrary from
what they are striving al, and they create
source of imminent danger.
'1he loads of nearly all nitro powders
are easured with the dip measure, which
affords ample accuracy. Three drains by
measure represent, according To the spe-
clfic weight of the different powders, from
3S 10 a grains by weight equal to 2.65 t6
2.78 grams. The corresponding charges
of Walsrode powder are smaller by weight
and in bulk /; they are, for 12-bore guns. 9.
and Il, or 81 and 80 grains.
"All propelliDg agents develop in sum
mer. and especially in warm and dry
weather, higher bursting strain than In
winter in a low temperature or moist at
mosphere. and fine shot again creates
owing 10 tho larger surface of friction, a
| higher gas pressure than the coarse ol
larger pellets. and the bursting strain oi
1B ounces is less than with IA ounces oi
the same size shnt.
In America much shooting is done in
summer and warm weather. A great mum.
Der of our celebrated shots prefer To load
for 12-bore ammunition 81 drains, instead
of the normal charge of drams. or ol
Walsrode powder 81 grains in place of 9!
grains, forgetting that these maximum
charges are only suited and intended fol
/ cold or wet weather."