A list of bullet abbreviations. This is by no means a complete list.

List provided by wikipedia.

ACC – Remington Accelerator [2]  (see sabot)
AP – Armor Piercing (has a steel or other hard metal core)
BBWC – Bevel Base Wadcutter
BEB – Brass Enclosed Base
BJHP – Brass Jacketed Hollow Point
Blitz – Sierra BlitzKing
Bt – Boat-tail
BtHP – Boat-tail Hollow Point
CB – Cast Bullet
CL, C-L – Remington Core-Lokt
DEWC – Double Ended Wadcutter
DU – Depleted Uranium
EVO, FTX – Hornady LEVERevolution Flex Tip eXpanding
FMJ – Full Metal Jacket
FMC – Full Metal Case
FN – Flat Nose
FP - Flat Point
FST – Winchester Fail Safe Talon
GC – Gas Check
GD – Speer Gold Dot
GDHP – Speer Gold Dot Hollow Point
GS – Remington Golden Saber
HBWC – Hollow Base Wadcutter
HC – Hard Cast
HP – Hollow Point
HPJ – High Performance Jacketed
HS – Federal Hydra-Shok
HST – Federal Hi-Shok Two
J – Jacketed
JFP – Jacketed Flat Point
JHC – Jacketed Hollow Cavity
JHP – Jacketed Hollow Point
JHP/sabot – Jacketed Hollow Point/sabot
JSP – Jacketed Soft Point
L – Lead
L-C – Lead Combat
L-T – Lead Target
LFN – Long Flat Nose
LFP – Lead Flat Point
LHP – Lead Hollow Point
LRN – Lead Round Nose
LSWC – Lead Semiwadcutter
LSWC-GC – Lead Semiwadcutter Gas Checked
LWC – Lead Wadcutter
LTC – Lead Truncated Cone
MC – Metal Cased
MHP – Match Hollow Point
MK – Sierra MatchKing
MRWC – Mid-Range Wadcutter
NP – Nosler Partition
OTM – Open Tip Match
OWC – Ogival Wadcutter [3]
PB – Lead Bullet
PB – Parabellum
PL – Remington Power-Lokt
PSP – Plated Soft Point
PSP, PTDSP – Pointed Soft Point
RN – Round Nose
RNFP – Round Nose Flat Point
RNL – Round Nosed Lead
SJ – Semi-Jacketed
SJHP – Semi-Jacketed Hollow Point
SJSP – Semi-Jacketed Soft Point
SP – Soft Point
SP – Spire Point
Sp,SPTZ – Spitzer
SpHP – Spitzer Hollow Point
SST – Hornady Super Shock Tip
SSp – Semi-Spitzer
ST – Silver Tip
STHP – Silver Tip Hollow Point
SWC – Semiwadcutter
SX – Super Explosive
SXT – Winchester Ranger Supreme Expansion Technology
TC – Truncated Cone
TMJ – Total Metal Jacket
TNT – Speer TNT
VMAX – Hornady V-Max Ballistic tip
VLD – Very Low Drag
WC – Wadcutter
WFN – Wide Flat Nose
WFNGC – Wide Flat Nose Gas Check
WLN – Wide Long Nose
X – Barnes X-Bullet
XTP – Hornady Extreme Terminal Performance