I've got a couple of more movies with realistic (though not 100% so) combat depictions y'all might want to track down at some point:
1. The Odd Angry Shot -- the Aussie Vietnam experience. Captures a lot of the tension and boredom of the jungle war without the Oliver Stone nonsense.
2. The Bridge, with Jimmy Stewart (who knew a few things about combat himself), set in Sichuan Province, China during the '44 Ichigo offensive. Not much combat, but what's in there is pretty damn good.... and at proper combat ranges too.
My main beef with SPR was that most of the final battle took place at way too close quarters, even for a city fight. Once the enemy is within sub 30m. grenade/SMG range, you don't get up and run around the way both sides were doing the whole time. You crouch in your selected hole pissing yourself and unable to see much of anything, or if you feel really motivated, you crawl like a snake. And if you're plain nuts or want to win a posthumous medal, you might engage in a brief heroic dash.... real brief.
3. The Sand Pebbles (Steve McQueen). The actual hand to hand fighting is standard Hollywood choreography, but this is one of the few movies that actually has the characters using sensible military tactics, both in the river battle and at the end. A great movie movie too and one of my favorites in any genre.
4. Oddly enough, the brief combat clips done by Kubrick in Dr. Strangelove(!) are in an authentic, grainy "combat camera" style that I suspect Spielberg drew upon.
"A great.... fatigue came over me..."