In no particular order:

.50 M2 machinegun
M 60 machinegun
M 14
M 16 (alot....too much)
M 1 carbine
M 1 Garand
Type 99 7.7mm japanese
8mm Spanish mauser
6.5mm Italian Carcano carbine
9mm pistol (any number of types of automatic)
45 cal pistol (including one interesting one that was a revolver using special little clips to give the rounds a rim for use in the gun)
.22 rifles
12, 16 and .410 gage shotguns (various sorts)
L7 and L8 37mm non-lethal munitions weapons
pepperball air rifle
.38 pistol
.380 pistol
.44 magnum pistol
.303 SMLE
M1859 Sharps .54 cal rifle and carbine
Remington 45/70 M1898
Sharps 45/70 carbine
.222 remington
400 Weatherbee
SKS
AK 47 (7.62)
7.62 Mosin Naguat
.303 Ross (Canadian...very scary gun with a very weak action)
Martini-Henry
.30 Winchester / Henry
40 cal Manard High Wall
Well, I know I'm forgetting a bunch here too but I think this is a good picture.