Joe (Zoe Saldana) is seen retrieving a SIG-Sauer P365X fitted with a reflex sight in Episode 2, "The Beating".
Rifles
Heckler & Koch G28
Bobby (Jill Wagner) is seen using a suppressed Heckler & Koch G28 rifle with a SIG-Sauer TANGO6 low-powered variable optic in "Sacrificial Soldiers" (S1E01).
Heckler & Koch HK416
"Two Cups" (James Jordan) uses what appears to be a Heckler & Koch HK416 with a 10.5 inch barrel, EOTech sight with magnifier and AN/PEQ-15 ATPIAL.
CIA SOG operatives use a FN M240B Machine Gun while battling ISIS fighters in "Sacrificial Soldiers" (S1E01).
PKM Machine Gun
ISIS fighters are seen using PKM Machine Guns while attacking a CIA / SOG base in Syria during Episode 1, "Sacrificial Soldiers".
Other
Milkor MGL
A Milkor MGL is used to fire smoke grenades in "Sacrificial Soldiers" (S1E01). Based on the shorter barrel and barrel interior, this launcher is likely an airsoft replica.
General Electric GAU-8/A Avenger
The USAF A-10 Thunderbolt II ground-attack fighter jet is seen firing the General Electric GAU-8/A Avenger cannon at the ISIS onslaught in "Sacrificial Soldiers" (S1E01).
Taser Pulse+
Two Cups uses a Taser Pulse+ pistol during Episode 2, "The Beating".