For those who are interested in how the Mystics armed themselves. Note that all firearms listed here use polymer cased ammunition.

Pistols:
FN Five-seven Mk3 MRD
FN FNX-9
FN FNX-45
B&T Station SIX chambered in .45 ACP
PSS-2
OTs-38

SMGs:
FN P90 Tactical
B&T KH-9

Shotguns:
Ithaca 37
Benelli M4 Super 90
Standard Manufacturing SSR

Assault Rifles:
FN F2000 Tactical
FN SCAR-L Mk2
FN SCAR-SC chambered in .300 BLK
M4A1/M16A4 RO901 and RO905 chambered in .458 SOCOM

Battle Rifles:
True Velocity RM-277R
True Velocity RM-277AR
FN SCAR-H Mk2

Machine Guns:
True Velocity RM834 chambered in 6.8 TVC
True Velocity RM338
FN M240 chambered in 6.8 TVC
FN HAMR IAR

Marksman Rifles:
FN SCAR Mk20 SSR chambered in 6.5 Creedmoor
FN SCAR MK20 CSR chambered in 6.5 Creedmoor

Sniper Rifles:
FN Ballista chambered in 338 Lapua
FN SPR

Launchers:
FN EGLM
Northrop Gunman PGS

Mounted/Aircraft Guns:
General Dynamics GAU-19
General Dynamics GAU-22
Mk. 19 Grenade Launcher
.50 AN/M3

Grenades:
Scalable Offensive Hand Grenade
M67 Frag Grenade
M18 Smoke Grenade
M84 Stun Grenade