Assault Rifles:

M4 = M4 (a mix of AR-15-style guns, not based on a specific model)

TAQ-56 = FN SCAR-L

Kastov 762 = AK-103

Lachmann-556 = Heckler & Koch HK93A2

STB 556 = Steyr AUG A3

M16 = M16A3

Kastov-74u = AKS-74UN

Kastov 545 = AK-105

M13B = SIG-Sauer MCX VIRTUS (added with Season 1)

Battle Rifles:

Lachmann-762 = Heckler & Koch HK91A2

SO-14 = M14

TAQ-V = FN SCAR-H

FTAC Recon = Like the M4, this is just another generic AR-15 variant, not based on a specific model. It's a mil-spec M16 receiver with a mix of AR-15 parts

SMGs:

VEL 46 = Heckler & Koch MP7A2

MX9 = Steyr AUG A3 9mm XS

Lachmann Sub = Heckler & Koch HK94A3 (modified to resemble an MP5A5)

Vaznev-9K = PP-19-01 Vityaz

FSS Hurricane = AR-57

Minibak = PP-19 Bizon-2

PDSW 528 = FN P90 TR (stylized)

Fennec 45 = KRISS Vector

BAS-P = SIG-Sauer MPX (added with Season 1)

Shotguns:

Lockwood 300 = Browning Cit0ri 725

Expedite 12 = Benelli M4 Super 90

Bryson 800 = Mossberg 590

Bryson 890 = Mossberg 590M

LMGs:

Sakin MG38 = IWI Negev NG7

HCR 56 = Steyr AUG HBAR-T

556 Icarus = FightLite MCR

RAAL MG = SIG-Sauer MG 338

RPK = RPK

RAPP H = Heckler & Koch HK21

Marksman Rifles:

EBR-14 = Mk 14 MOD 0 Enhanced Battle Rifle (M14 variant)

SP-R 208 = M24 SWS

Lockwood Mk2 = Marlin Model 336

LM-S = Heckler & Koch SR9(TC)

SA-B 50 = M24 SWS (in custom chassis)

TAQ-M = FN SCAR 17S

Sniper Rifles:

MCPR-300 = Barrett MRAD

Signal 50 = Gepard GM6 Lynx

LA-B 330 = M24 SWS

SP-X 80 = Remington M2010 Enhanced Sniper Rifle

Victus XMR = Accuracy International AW50 (added with Season 1)

Pistols:

P890 = SIG Sauer P220 Elite

.50 GS = Desert Eagle Mark XIX

X12 = Glock 17 MOS (stylized)

Basilisk = Smith & Wesson Model 500

X13 Auto = Glock 18

Launchers:

PILA = SA-25

Strela-P = Carl Gustaf M4

JOKR = FGM-148 Javelin

RPG-7 = RPG-7