This is a random list of the many guns I know of, and it's not even the full list:

PISTOLS:

S&W 9mm
S&W Sigma
S&W Sigma Compact
S&W .40 caliber
S&W 9mm/.40 Compact
S&W 10mm
S&W J frame
S&W K frame
Beretta
Beretta 96D
Beretta Cougar
Beretta Compact
Beretta Cougar Compact
Browning
Desert Eagle .45 caliber
Desert Eagle .50 caliber
FN Forty-Nine
Glock
Glock Compact
Glock Sub-Compact
Glock 10mm/.45 caliber
Glock 10mm/.45 Sub-Compact
Glock G36
H&K P2000
H&K P2000 Compact
H&K USP
H&K USP Compact
H&K USP Sub-Compact
H&K USP .45 Compact
Kahr
SIG 220/226
SIG 228/229
SIG 239
SIG P2022
SIG P225
SIG P245
SIG Pro
Walther 99
Tokarev TT-33
(SIG?)P228
FN Five-seveN USG
Webly
Nagant M1895
Manurhin MR73
Arminius Model 10
Korth Combat
Rast & Gasser M1898
Miroku .38
IzMech MP412 "REX"
Bulldog
Colt Python
Ruger Redhawk

SEMI-AUTOMATIC GUNS:

Thompson
P90
Uzi
MP7
Tippmann A5
Colt 9mm
H&K SMG 2
SMG-PK
SKORPION
MP-40
Type 55 .8mm
Vector SMG
M12
Mac 11
K7
Micro-Uzi
Beretta SMG
Type 100 SMG

CARBINES:

M16
M16A2
M16A3
M4
M4A2
M4A3
M1 Carbine
.45 ACP
M14
H&K G36K
L85A1
SA-80
H&K UMP
H&K MP5

SHOTGUNS:

Franchi SPAS-12
Franchi SPAS-15
Benelli M1 Super 90
Beretta 1201 F/FP
Fabarm SDASS Tactical
Pancor Jackhammer
AA-12
Valtro PM-5
Nazarian 870 Combat
IZHMASH Saiga 12
TOZ-194
Vepr 12
Striker/Protecta/Streetsweeper
Ithaca Model 37
KAC Masterkey gun attachment
Mossberg 500
Remington 1100
Serbu Super-Shorty
USAS-12

ROCKET LAUNCHERS:

RPG-7
M203 launcher attachment
MM-1
EX-41
M79
MGL-Mk. 1

I'd put more up, but I'm running out of characters. So, here's a picture of all kinds of guns, many of which I already mentioned

Oh yeah, and I now officially worry myself. If I know so many weapons, hell, I could become Public Enemy Number One.

Somebody help me...