Billy Butcher (Karl Urban) threatens Madelyn Stillwell (Elisabeth Shue) with what appears to be a Beretta 92FS Inox in "You Found Me" (S10E8). The pistol is seen lying on a table in darkness.
Glock 19
CIA Deputy Director Susan Raynor (Jennifer Esposito) pulls what appears to be a Glock 19 on Butcher (Karl Urban) after he breaks into her home in "Cherry" (S1E02).
Frenchie's girlfriend Anika (Jordana Lajoie) is seen pointing an FN P90 TR at herself in "Cherry" (S1E02).
Heckler & Koch MP5A3
A Heckler & Koch MP5A3 with an S-E-F trigger group is used by one of the armored truck robbers to threaten a teenager in "The Name of the Game" (S1E01), but it is melted by the Homelander's heat vision before he has a chance to use it.
The M4A1 carbine is seen used by various characters in the series. Frenchie is seen field stripping an M4 with the standard cylindrical handguards in "Cherry" (S1E02). ESU officers and a gunman are armed with the M4A1 in "Get Some" (S1E03). "Wee" Hughie Campbell (Jack Quaid) uses one with an RIS handgard and various accessories in a shootout with a Vought International tactical team in "You Found Me" (S1E8), hitting one in the head and promptly apologizing to him for it.
Mk 18 Mod 0
One of the armored truck robbers is armed with a plain Mk 18 Mod 0 and unloads it full auto on the Homelander with no effect in "The Name of the Game" (S1E01). US Navy SEALs are seen armed with Mk 18s fitted with various accessories during raids in Syria in "The Self-Preservation Society" (S1E07) and "You Found Me" (S1E08).
Zastava M70AB2
Gunmen seen attacking The Female (Karen Fukuhara) are armed with Zastava M70AB2 rifles in "The Female of the Species" (S1E4).
Sniper Rifles
Serbu BFG-50A
Billy Butcher (Karl Urban) is seen using a Serbu BFG-50A in an attempt to kill Translucent in "Cherry" (S1E02). He uses it again in "The Self-Preservation Society" (S1E7) to attack Annie January / Starlight.