Anti-Tank Gun?

I haven't seen the movie yet. I plan to today when it airs on TCM in a few hours. I do, however, play quite a few ww2 related games. What your describing sounds like a PTRD or PTRS-41 anti-tank rifle.

http://en.wikipedia.org/wiki/PTRS-41

http://en.wikipedia.org/wiki/PTRD

This gun features prominently in a realism based FPS PC eastern front ww2 game "Red Orchestra" The guns are notoriously hard to use as their penetration power is a bit lacking unless you get a good dead on hit. They are mostly effective against early war tanks, trucks, and lightly armored vehicles. They are not going to do much against the big German tanks like the Tiger, Panther, etc.

It appears to be a Boys anti-tank gun developed by Britsh Captain Boys in 1937. It was .55 cal and had a very heavy recoil. It was effective on armor up to 3/4 of an inch. It would have been quite effective had it been around for WWI as the armor of tanks of that era was only about 1/2 in. In WWII it was widely used against unarmored vehicles and bunkers. It was used by US forces in the Pacific to good effect against the early relatively lightly armored Japanse tanks. Later Japanese tanks had heavier armor that the Boys rifle bullet was unable to penetrate. If any one has any further info or a different opinion please post it.