The M1911A1 is seen in the hands of Holnists, to include General Bethlehem (Will Patton), and is also used by The Postman (Kevin Costner) when he escapes from the Holnists.
General Bethlehem (Will Patton) carries a Pre-Model 10 Smith & Wesson M&P as his sidearm. The same revolver was used just moments before by Ford Lincoln Mercury (Larenz Tate). It's identifiable as a Pre-Model 10 because of the hammer, front sight and the ejector rod design.
Colt AR-15 Sporter I Carbine (mocked up as XM177E2)
The Holnists use Colt AR-15 Sporter I Carbines, fitted with mock flash moderators to pass for XM177E2s, that are subsequently taken and used by several other characters including The Postman (Kevin Costner) as well as Abby (Olivia Williams). They were seen firing in semi-auto, further indicating that they are mocked-up civilian models (that in this instance weren't converted to full auto).
An M1 Carbine is carried by the Postman (Kevin Costner) at the beginning of the film. He loses it when he gets captured and it's never seen again. Near the end of the movie members of the Postman's army can be seen carrying M1 Carbines as well.
Error creating thumbnail: File missingKorean War Era M1 Carbine, with birch stock, adjustable sight and bayonet lug - .30 Carbine. Most of the World War 2 variations of the M1 Carbine were sent back to government arsenals and retrofitted with the bayonet lug and adjustable rear sight. This is the version seen after late 1945 and all the way until the 1960s.Error creating thumbnail: File missingThe Postman (Kevin Costner) walks through the remains of Salt Lake City with his faithful mule Bill and his trusty M1 Carbine.Error creating thumbnail: File missingThe Postman (Kevin Costner) explores an abandoned gas station.Error creating thumbnail: File missingThe Postman looks around inside the gas station with his M1 Carbine at his side.Error creating thumbnail: File missingThe Postman readies his M1 Carbine. This shot shows the bayonet lug and adjustable rear sight, indicating it is a 'post-war'(World War II) variant.
One of the Holnist soldiers is armed with what appears to be an FN FAL with mounted Cobray CM203 (standing in for the M203 grenade launcher). This appears to possibly be one of the same prop weapons previously used in the film Escape from L.A..
One of the many Holnist soldiers appears to be carrying an AK-47 Variant. Unable to determine the exact model. Despite my best efforts the only shot I could find of it remained blurry. However it's likely that it's an AKM considering that the movie was filmed within the continental United States in 1997 and the AKM often served as a double for the AK-47 during the eighties and nineties.