I've been trying to identify several series of military sci-fi that I read in the early 90's. I've had more luck remembering details of some than others.
For this particular series, the only details I can remember involve the standard troop weapon. It was a rifle that fired "flechette" rounds (as they were called in the books). Ammunition for the rifle was a solid block (plastic, I believe.) When fired, the mechanism in the weapon shaves slivers (flechettes) off of the solid block and launches them at an extremely high rate of fire.
Also, IIRC, the standard weapon also had grenade launchers that launched small spherical contact fragmentation grenades.
The characters were human, and the war/combat was the focus of the books, not a sidebar. The main characters were soldiers in the unit that was the focus of the overarching plot of the series. Futuristic, planet-side, not on Earth. It's likely the series took place on multiple planets.
I remember a scene with a unit commander ensconced in a mobile command center while planning a battle, in which he opted to ignore the computer's weather forecast and asked a farm-boy trooper for his opinion on what the weather would do that night (rain by dawn). Although, I'm not 100% certain that this is from the same books as all that's been mentioned before. I could be mixing my series on this detail.