A nickel plated Colt Detective Special is carried by Chicago patrolman George Stone (Andy Garcia) as his backup gun, which he tosses to Ness during the train station shootout.
Officer Stone (Andy Garcia) uses a Colt Official Police while on the police academy firing range. The court officer is later seen with one that he lends to Ness for him to chase Nitti down. What is interesting about Ness's gun is that this particular version of the Official Police is actually a Post-War gun (meaning it wasn't made until after 1950) whereas this movie takes place in the 1930s. The ramped front sight, flat hammer and longer ejection rod cap are changes that were made after 1950. Pre-War guns would have a halfmoon front sight and shorter ejector rod cap.
Treasury agent Elliot Ness (Kevin Costner) uses an M1911A1 throughout the film in scenes in which he is not firing his weapon. Treasury accountant Oscar Wallace (Charles Martin Smith) keeps one in a shoulder holster. Several of Capone's (Robert De Niro) mobsters carry them.
Treasury Agent Elliot Ness (Kevin Costner) carries a Star Model B as his sidearm in the film, standing in for the M1911A1 in scenes in which he fires it. A gangster who holds the bookkeeper (Jack Kehoe) from Ness and Stone in the train station holds a Star Model B to the bookkeeper's head. Frank Nitti (Billy Drago) carries a nickel-plated Star Model B in court, which Ness uses as an excuse to kick him out.
[[Image:Untouch-1911g.jpg|thumb|none|500px|Nitti reloads his nickel Star Model B's.
Some of these still look like Colt M1911A1s, while others are Star Model B's--User: Colt Revolver Fan
Smith & Wesson Model 10
A Smith & Wesson Model 10 is carried by Stone (Andy Garcia). He uses it to kill the gangster who is holding the bookeeper hostage at the end of the shootout in the train depot. Malone (Sean Connery) also carries one, which he infamously uses to shoot an already dead gangster. Many other Chicago policemen carry Model 10s.
Many gangsters and policemen use the Thompson M1928 during the film. Stone and Malone use them to great effect during the Canadian shootout. Frank Nitti notably uses one to fatally wound Malone outside his apartment.
According to the Ellis Props & Graphics NFA weapons list available on Long Mountain Outfitters' web site, there was a mix of M1921s and M1928 Thompsons used in the film. -MT2008
The leader of the Royal Canadian Mounted Police is seen firing a Webley MK IV into the air when he prematurely launchs the assualt on Capone's men at the border.
Error creating thumbnail: File missingM1917 Enfield .30-06. The Pattern 1914 was chambered originally in a high velocity .276 caliber and then changed to .303 British when the experimental caliber proved to be troublesome. Remington manufactured the rifle for the British in WW1. After the U.S. joined the Allies it was easy to convert the rifle to 30-06. Which was important since the Federal Springfield Armory could not produce enough of the 1903 Springfield rifle to meet war demands.United States troops carried both the 1917 Enfield and the 1903 Springfield in World War I.Error creating thumbnail: File missing"Mounties" with a P-14 Enfields slung over their backs.Error creating thumbnail: File missingMore Mounties with P-14 Enfields over their backs.
A Winchester Model 1912 is used by Elliot Ness (Kevin Costner) during the shootout in the train station. These are also used during the shootout on the Canadian/U.S. border.
An 12 Gauge Rossi Overland sawed-off shotgun is kept by Malone (Sean Connery) in his apartment as a "home defense" weapon. The Rossi Overland sawed-off shotgun was built by the late gunsmith Branko Wohlfahrt for Ellis Mercantile.
