not exactly guns, but how 'bout arrows? - The Gladiator - This one fits in the realistic, not BOOM BOOM loud category - arrows just dont make that much noise.
Best Gunshots
The hallway shootout in the matrix? No. Backing out the door in last man standing? Uh Uh. How about the mini-gun in Armageddon? Nope. Dug deep in the CD collection today and came out with Mercury Living Presence 1812 Overture, etc. Everyone knows the cannon fire in the 1812 but I had completely forgotten the WAR fought between the speakers in Beethoven's "Wellington's Victory". My neighbor's ears are bleeding.