Yes, The Kingdom was very good.
Open Range is probably the best cowboy shootout ever filmed.
But, for the best gun battle ever filmed, you need to go back to Northwest Passage, with Spencer Tracy. The Rangers attack on the Abenaki village is a classic! It was filmed in real time, starting just at dawn, and finishing up a few hours later. Lots of shooting and hand-to-hand, plus a great shot, looking over a Rangers shoulder as he tracks a running Indian and shoots him. And the best part of it is, it's a true story!
Grizzle Bear