I'm sorry I can't be very specific about particular scenes, but there are intense sections (but not usually involving explosions, etc.) in these movies:
Traffic
Deliverance
Jaws
Shackleton
Monanieba (Repentance)
Tora Tora Tora
Special Bulletin
The Manchurian Candidate (the original)
HTH a little.
Cheers,
Scott.
(Who hopes you don't go overboard with this immersion stuff. :-)