Continuity mistake: When Blondie abandons Tuco in the desert, watch the rope around Tuco's neck. It changes between shots, sometimes over his left shoulder, and sometimes hanging down in front of him. It is not due to the camera angle.
Continuity mistake: When Blondie is saved by the mortar shell, and it shows the empty noose, it is completely different than the noose that Blondie had around his neck. The loop that the noose went through to hold it to the beam has changed.
Revealing mistake: When Blondie is to be hanged by Tuco, and saved by an extremely lucky hit by a Union mortar, you can see that the wall that will be hit by the grenade has been blown to pieces at least once before; the bricks have no mortar between them, and there is a large circular scorched area on the brick wall. (00:47:10)
Continuity mistake: When Blondie and Tuco are planting dynamite to blow up the bridge, they are standing in the water. During the following blast, they are hiding away next to the river and from then on, they are totally dry again.
Revealing mistake: After the explosion blows a hole in the wall and Tuco joins the procession of people flowing down the street, when the shot switches to face the characters you can see that the 'woman' in a blue dress in the wagon is actually a man. (Time is for the extended version of the film). (01:59:15)
Revealing mistake: When Tuco makes Blondie march through the desert, there is a shot at the very beginning and Blondie looks over his shoulder, feeling the strain of the desert. Then the camera focuses on Tuco and in this shot, you can see the tracks in front of his horse from a previous take.
Visible crew/equipment: When Angel Eyes has finished paying the legless man for information, the legless man hops into the saloon. Notice he has two shadows, revealing the presence of stage lighting.
Factual error: Just before Angel Eyes confronts the girl in her room about the whereabouts of Bill Carson, we see her walking in the hall outside her room, and lighting this hallway is a very modern day lightbulb.
Visible crew/equipment: When Angel Eyes sits down at the dinner table in his first scene, there is a small unlit lantern hanging on the wall near his head, and unexplainable light sources reflected on it.
Continuity mistake: A dirty Union cavalry officer hits himself to clean off the dust that made him appeared Confederate. His first two strikes barely shake the dust on his uniform, yet, after a cutaway and two off-screen strikes, his arm is almost completely free of dust. (01:16:50)
Revealing mistake: When Tuco is about to shoot Blondie in the desert, and the Army wagon is seen approaching, the driver can be seen sitting far back in the rear of the coach wearing a hat. (00:54:10)
Revealing mistake: When Tuco first enters Sad Hill Cemetery, you can see the dual tire track ruts left by the dump truck that brought in the sand to make the grave mounds.
Answer: There's a show called "Hollywood Weapons: Fact or Fiction" which dealt with this exact question (s01e03). Blondie is roughly 200 yds away. In the show the host didn't hit the rope, but only missed by an inch on his first attempt. I definitely think an expert Sharps Rifle shooter could make the shot. The issue however, is the bullet would most likely not actually slice the rope apart as seen in the film (they fired the Sharps at point blank and the rope remained partially intact still). They also tested shooting a hat off someone and (as expected) the bullet just goes right through the hat without lifting the hat at all.
Bishop73
That was another thing that puzzled me. On several occasions in this film, Tuco is suspended from a rope, and Blondie cuts the rope by firing a bullet at it, (I think Clint Eastwood repeated the trick in "The Outlaw Josey Wales"). But if you fired a bullet at a rope holding a (rather large) person like Tuco (or a similarly heavy weight), even at close range, would it really sever the rope? I will have to look out for "Hollywood Weapons Fact Or Fiction." I hope they only used a dummy or a model to re-create the shooting feats. I don't think I would have liked to have been hanging on a rope while somebody fired bullets at me to see if this would sever the rope, or to stand there while they fired bullets into my hat to see if they could lift it off my head.
Rob Halliday