13 Two of the landing crafts that you see in the Omaha Beach scenes were actually used in World War II. 

14 Saving Private Ryan was the last movie edited non-digitally to win the Academy Award for Best Film Editing. 

15 During the landing scene, the maimed American soldiers were actual amputees hired from all over Ireland. 

Around twenty to thirty amputees were recruited for the scene so that the war injuries would be realistic. Apart from the 1,500 extras hired to play the soldiers, there were as many as 400 crew members involved during filming of the scene which Spielberg turned into an unforgettable masterpiece.(1, 2)

16 Over forty barrels of fake blood were used for the Omaha beach scene to simulate the effect of blood in seawater. 

The scene depicts many soldiers being shot underwater and the filmmakers had to use underwater cameras to shoot the scenes. The scene has so many deaths that there were pools of blood with even the seawater and waves getting stained red. It required considerable amounts of fake blood to show the intensity of what happened during the war.(source)

17 The combat scenes in the movie were filmed so realistically that the D-Day veterans left the theaters unable to finish watching the opening scene. They said that it was the most realistic depiction of the combat they’ve ever seen. 

The opening scene of the movie shows the US army troops landing on Omaha Beach and then engaging in a battle with the Germans. The scene is said to have shown a very historically accurate account of what happened when the landing crafts came towards the shore. For them it had become an emotional experience reliving the past and the trauma of death and destruction.(1, 2)

18 Stephen Ambrose, a military historian and author, had to ask the special screening for him to be halted after 20 minutes because the opening scene was too intense for him. It took him a few minutes to compose himself before returning to the screening room and finish watching it.