H&K G28E from 2016 SHOT show
H&K was awarded this contract which has fixed cost of $44.5 miliion. Other finalists were LMT and FNH USA. The firearm H&K submitted is reportedly G28E1.
According to Soldier Systems Daily, there is some possible indication that this could replace M110.
http://soldiersystems.net/2016/03/31/rumor-has-it-hk-wins-csass/
http://soldiersystems.net/2016/04/01/confirmed-hk-wins-csass/
From: Soldier Systems