Quote History never thought much of that scene
most obvious sin is shotgun throwing people
Other sins
-opening shot to the head wasn't followed up fast enough by the next guy getting shot
-Infinite shot rifles, you can possibly assume he reloads it's just not shown until his gun goes click and he doesn't reach for a reload and finds his supply empty too
-either a 9 shot revolver or showing the same shot from other angles/time repeat (acceptable) but for supposedly skilled gunmen why dump all 6 shots into a dying man, leaving yourself empty
-kick through the wall rather than going around
-flankers were noted then ignore because of script magic, a good gunfight movie would have shown their effectiveness or had the good guys counter
-guys up top with great vantage point do nothing until it's time for them to take their turn at getting shot
-plenty of time to set your hat on the ground, pile up some bags/pillows for some reason in some sort of makes-no-sense-ambush
-easier to go around and use a door than kick through a wall
-generally the side that's smart enough to use cover comes out ahead.
I do in general like the costumes and guns, and I like the fact that 2 can beat many with skill, and that an opening explosion of violence can accomplish a lot while the other side reels and attempts to recover.