Browning M2HB (mocked up as KPV heavy machine gun)
The Jackal (Bruce Willis) buys a heavy machine gun from his contacts via online called a "Polish ZSU-33 14.5mm", which is in reality a Browning M2HB mocked up as a KPV heavy machine gun in 14.5mm. Both guns have a cyclic rate of ~600RPM so how they got away saying it fired 1400RPM is unknown. The rounds Jackal uses are Depleted Uranium rounds, which he claims he uses for better "sprawl" on impact, even though in reality they are used because they are heavy i.e. more accurate. He notabley uses it twice in the film, once to kill Ian Lamont (Jack Black), the man who built the automated mount for him, and again to try to assassinate The First Lady (Tess Harper). The mocked up weapon was supplied by Stembridge Gun Rentals.
A standard non-mocked up Browning M2HB is seen mounted on a humvee in a military base.
The Jackal (Bruce Willis) uses a Heckler & Koch HK94 chopped and converted to resemble a Heckler & Koch MP5A3 fitted with a fake "integral" suppressor to make it an MP5SD3. He uses it to dispatch the FBI agents in Isabella Zanconia's (Mathilda May) house.
SIG-Sauer P228
Richard Gere uses a SIG-Sauer P228, a compact 9mm handgun, when he joins the FBI.
SG-1 with a normal G3 buttstock (cheekrest on top) and what appears to be a harris type bipod instead of the regular one. Semi auto only unlike a normal G3. Not a PSG-1 due to having iron sights.