Other mistake: Interior Minister Roger Frey advises Commissioner Lebel that all members of the police, military and other security forces attending the ceremonies on the day the Jackal is expected to strike will be issued with lapel badges at the last moment, in case he is going to try to masquerade as one of them. We see hundreds of such people in the next part of the film, including Lebel himself and the CRS private who allows the heavily disguised Jackal through the barricades around the site of the ceremony DeGaulle is due to attend. Only the CRS private wears a lapel badge. Not one of the other police or military officers in attendance is wearing a lapel badge of any kind. (01:58:15)
Other mistake: Towards the end of the film the Jackal, in disguise as the fictional one-legged, grey haired Frenchman Andre Martin, finishes setting up his sniper's nest and removes his beret, revealing that he has only dyed his hair grey where it protruded. He has a circular mop of his normal chestnut brown hair under his hat! This is an incredibly stupid thing to do - it is a perfectly normal thing for a policeman (or any other security operative) to ask that someone showing identity papers remove his hat if he is wearing one. The Jackal is a professional assassin who meticulously prepares for all contingencies - he isn't going to throw away his whole plan for the sake of a bit of extra hair dye. (02:10:05)
Other mistake: The Jackal goes out into a field to test his gun and adjust the sights. But the gun is then dismantled again, so the adjustments are irrelevant.
Chosen answer: According to Wikipedia: "Cordite is a family of smokeless propellants made by combining two high explosives: nitrocellulose and nitroglycerin, i.e. it is a double-base propellant. However, Cordite N, a triple-base propellant is also used. Cordite is classified as an explosive, but it is normally used as a propellant for guns and rockets." So yes, it works.
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