I forgot to mention, make sure you really play up the rumbling from shells that pass by overhead, esp if the Russians are throwing anything 200+ mm at them. And the concussion as was previously mentioned. Maybe make a reference to teeth feeling like theyre going to shake out of their skulls.
And definitely do as Grimace suggested and have some NPCs get blown up. Esp. if theyre just missing legs and do a lot of screaming and bleeding on everything before they die. Gives the team medic something to do, too.
