The following weapons were used in the film Alien Uprising (aka UFO):
A SIG-Sauer P226R is pulled by Michael (Sean Brosnan).
SIG-Sauer P226R - 9x19mm, updated P226 with accessory rails, now the standard production version for the P226 (IMFDB still refers to this model as the "P226R" to distinguish between newer and older models).
A Glock 17 is seen used by British soldiers.
Glock 17 (2nd Generation) - 9x19mm.
Mossberg 500 Cruiser
George (Jean-Claude Van Damme) is seen armed with a Mossberg 500 Cruiser.
Mossberg 500 Cruiser with plain barrel, no heat shield - 12 gauge
Black Ops soldiers (all portrayed by Joey Ansah) appear to carry M4A1 rifles.
Heckler & Koch G36K
A British soldier is seen with a Heckler & Koch G36K with a C-style railed carry handle.
Heckler & Koch G36K with C-style railed carry handle - 5.56mm
Heckler & Koch MP5A3
A Met Police officer (Joey Ansah) is seen with a Heckler & Koch MP5A3.
Heckler & Koch MP5A3 with "tropical" (wide) forearm and stock extended - 9x19mm