Submarines and their Weapons - Aircraft of World War II

series of grooves in the body of the bullet. By that
means, the velocity of the projectile was much
increased, since its cross-sectional area had been
diminished considerably while the pressure in the barrel
remained constant (the velocity being a product of
the two). Unfortunately for Puff, the complexities of
manufacturing a rifled tapered bore were beyond the
capability of German gunmakers, and nothing came
of the idea, at least, not then.
In the 1930s, another German, a gunmaker named
Hermann Gerlich, experimented with Puff's scheme,
and was able to manufacture hunting rifles according
to the principle. They proved to be excellent, with the
all-important flat trajectory, but when he tried to interest
the armed services of a number of countries in
such a rifle, he was less successful, entirely, it seems,
thanks to the projected cost of the weapon. However,
the Springfield Arsenal, for one, certainly validated
the concept, producing a version of the M1917 rifle
with a muzzle velocity of over 2135m/s (7000ft/s)
instead of the standard 855m/s (28QOft/s). Gerlich
gave up trying to market the concept himself in 1933,
and contacted Rheinmetall, who saw the possibility of
incorporating the system into an anti-tank rifle, using
a projectile with a tungsten carbide core and soft steel
skirt. Eventually, it produced what became known as
the Panzerbüchse (anti-tank rifle) 41, which fired a
20mm (it had started out at 28mm nominal diameter)
round at a muzzle velocity of around 1400m/s
(4600ft/s), and which could perforate (ie, pass completely
through) 66mm (2.6in) of nickel-steel armour
at a range of 500m (1640ft). Soon, Rheinmetall produced
a more powerful version in 4.2cm nominal calibre,
which squeezed its projectiles down to 29.4mm,
and which could perforate that same thickness of
armour plate at twice the distance. It entered service
in 1941 as the 4.2cm Panzerabwehrkanone (anti-tank
gun) 41, and proved to be very successful.
THE SQUEEZE-BORE GUN
Two years earlier, Krupp had also begun to examine
the possibilities of reducing the cross-sectional area
of a projectile while it was in the barrel, and settled on
a slightly simpler, but no less effective, method of carrying
out the procedure. Instead of manufacturing a
barrel with a uniformly tapered bore, Krupp added a
smooth-bore, step-tapered section to the muzzle of a
conventional gun. The (flanged) round entered the
supplementary section at nominal diameter of 7.5cm
and passed through two tapered sections which
reduced it to 5.5cm. The advantage of this was chiefly
TANKS AND ANTI-TANK WEAPONS
Above: The 8.8cm Raketenwerfer 43, usually called the
'Püppchen', was not a gun but a rocket launcher. It was
superseded by the shoulder-held tube rocket launchers,
logistical; only the unrifled, tapered section became
badly worn (that, of course, was the system's great
drawback), and was attached to the main section of
the barrel by a simple screw collar, which meant it
could be replaced in the field without the need for
special tools. The 7.5cm PaK 41, as the gun was
known, fired a tungsten-cored shot weighing 2.6kg
(5.71b) at a muzzle velocity of 1125m/s (3700ft/s) and
could perforate 125mm (4.9in) of armour, more than
any tank had, at a range of 2000m (6560ft). This gun
was the weapon originally specified for the Tiger
tank. The taper-bore and squeeze-bore guns were
without question excellent battlefield weapons, but
they needed tungsten for their bullet cores if they
were to be effective, and that was a material in short
supply in Germany at that time, being much in
demand in the engineering industry as cutter bits for
machine tools. Eventually, a choice had to be made,
and the manufacturing industry won. The taper-bore
and squeeze-bore guns were taken out of service and
scrapped and few survived the war. Rheinmetall and
Krupp offered conventional anti-tank guns in larger
calibres instead, culminating in the 12.8cm PaK 44.
SHAPED AND HOLLOW CHARGES
The kinetic energy of a very hard object travelling at
high speed (brute force, in other words) was one way
to perforate armour, but there was another; the shaped