Character mistake: When Travis is buying guns, Easy Andy (the gun salesman) makes a few errors. Firstly, he states that the Smith and Wesson 61 Escort is a "Colt .25 Automatic." Secondly, he calls the Astra Constable a ".380 Walther." And lastly, he talks about the ".380 Walther" saying "during World War II, they used this gun to replace the P38. Just given out to officers." This is also incorrect.
Character mistake: In the scene where the gun dealer is showing handguns to Travis, the dealer shows off a gun he says is a Walther PPK, but in fact is a Bersa Thunder, which has a differently shaped trigger-guard.