Manual

21
sures since these same pressures make possible the high velocities, flat tra-
jectories and increased range of modern ammunition. Yet, the modern fire-
arm is no stronger than the cartridge case that is used in its chamber. If the
case ruptures, the primer punctures or if the headspace is altered, hot pow-
der gases under extreme pressure will flow back through every seam in the
action possibly destroying the firearm and causing injury to the shooter
The propellant charge in a muzzleloader is poured directly into the bar-
rel of the firearm and then compressed by the projectile in the chamber
area. Think about this for a minute! Lacking the restraints and protection
supplied by a modern cartridge case, the muzzleloading charge rests direct-
ly against the steel chamber walls and the face of the breech plug. The igni-
tion port in a cap lock or flint lock is a simple hole leading directly into the
chamber. Certain surfaces of the breech plug and nipple are directly
exposed to chamber pressure. Judged by the design standards set for mod-
ern firearms, the muzzleloader is extremely primitive. Its design will not tol-
erate high pressure.
The following text applies to the use of your Thompson/Center muz-
zleloader with Black Powder or Pyrodex charges properly restricted to the
loading information shown in this booklet. It deals with those conditions
which singularly or cumulatively can affect muzzleloading pressures.
For years it has been assumed that it is impossible to overload a fire-
arm using Black Powder. The theory was that only a certain portion of a
heavy Black Powder charge will burn and that the remaining powder is
blown out of the bore in unburned condition. This thinking led to the belief
the pressures created by a Black Powder charge would reach a certain
(undetermined) range and climb no higher.
Our testing indicates that this
theory is completely unfounded
. As heavier and heavier charges were
loaded our pressure readings climbed accordingly. At no time was there any
indication of a leveling off of pressure.
Unreasonably heavy charges of
Black Powder or Pyrodex can be dangerous. Restrict yourself to the
loads listed in this booklet and start with the lightest load shown for
your particular model and caliber. Bear in mind that the following con-
ditions can be cumulative. If you load the heaviest charge listed with-
out following instructions (working slowly upward) then other condi-
tions such as powder fouling, hard projectiles and improper loading,
can carry you well beyond the maximum safe pressure range of muz-
zleloading firearms.
All propellant powders (depending upon their design
and composition) will function most efficiently within a given pressure
range. Our testing indicates that the Black Powder used in our testing oper-
ated most efficiently at or near the midway point in our loading charts, and
recorded the highest velocity in relation to the lowest pressure.
Heavier
loading showed marked increases in pressure and substantially more
recoil for only minor gains in velocity.