Information has been obtained concerning four 105-mm hollow-charge German shells in
addition to the 10-cm Gr 39 described in Tactical and Technical
Trends No. 31, p. 35. These are:
10-cm Gr 39 rot*
10-cm Gr 39 rot HL/A
10-cm Gr 39 rot HL/B
10-cm Gr 39 rot HL/C
The only difference between the Gr 39 and the Gr 39 rot is the size of the
rotating band and the fact that the Gr 39 is intended for use in
the 10.5-cm LG 40, airborne gun (see Tactical and Technical Trends No. 35, p. 20), and
the other three are intended for use in the l.F.H. 18 M, a field howitzer
with a muzzle-brake -- as indicated by "M"--Mundungsbremse (muzzle brake), -- see
Tactical and Technical Trends, No. 30, p. 10.
The Gr 39 rot is propelled by the normal charge -- the Gr 39 of the airborne
gun is a special munitions adapted for the open venturi breech of the
airborne "double ender". The other three shells are propelled by supercharges.
The sketches of the four projectiles clearly illustrate the progressive
improvement in shell design and the air space within the shell. The absence of
a flash-tube between the nose-fuze and the booster in the A, B, and C shells will
be noted. It may be that the firing of the booster is accomplished by detonation
rather than ignition.
*The adjective rot (red) frequently appears in the nomenclature of German
ammunition, and shells so designated have a red band painted above the driving
band. Such projectiles are used in guns and gun-howitzers like the 10.5-cm l.F.H. 18 M, but
not in true howitzers. They are reported to call for an extra increment of propellant.
HL is the German abbreviation for Hohl Ladung or hollow charge.