NOTES ON USAGE & ABBREVIATIONS

SHELLS

AP Armour Piercing (either shot or shell)
APC Armour Piercing Capped
APBC Armour Piercing with Ballistic Cap (but not an armour penetrating cap)
APCBC Armour Piercing Capped with Ballistic Cap
Common Nose-fuzed explosive shell (from the ACW into the 1890s)
CP Common Pointed (base-fuzed explosive shell)
CPC Common Pointed Capped
SAP Semi-armour Piercing shell (base-fuzed)
SAPC Semi-armour Piercing Capped
SAPBC Semi-armour Piercing with Ballistic Cap
SAPCBC Semi-armour Piercing Capped with Ballistic Cap

FILLERS

T TNT
BP Black Powder
PA Picric Acid
L Lyddite
S Shellite
SH Shimose
M Mellenite
W Wet guncotton
D Explosive D
A Ammonal/Amatol

NOTES

These shell classifications are not the official nomenclature. Rather, they are the actual functional 'type' from analysis. For example, a thin cased base-fuzed shell similar to the British type CP/CPC is called CP/CPC, regardless of what the 'official' nomenclature was. Likewise, a thick Cased base-fuzed shell like the German 'base-fuzed HE' is an SAP.

There is also a difference between CP and SAP. The former is intended to penetrate armour from about .33 to .5 caliber thickness. The SAP was to penetrate armour .5 to .67 calibers thick. The British AP Mk. I and Mk. II, which became the Japanese No. 1 and No. 2 shells, were really closer to SAP than AP, due to the large cavity for a c. 5% BP burster. AP caps and face-hardened armour changed the equations somewhat. Mike Ley believes that the IJN did NOT use CPC in the RJW, which seems to be confirmed by the fact that the British did not cap theirs until 1909...

Common shell was somewhat effective against thin armour (iron) of about .25 calibers. The later steel Common would have equal effectiveness against homogenous steel armour, or .33 caliber iron, but none against face-hardened. Anyway, the effect was to blow a hole in the plate, rather than penetrate.

Under the absolute best circumstances, AP/APC shells filled with Shimose [or any of the other picric acid derivatives] could not penetrate into the target. The burster was so sensitive that it would explode generally on contact, or at best in the process of penetrating the plate. In effect, this made the Japanese APC little more than base fuzed HE with a small burster.

Kent Crawford