Blue Ruin (2013).

http://www.imdb.com/title/tt2359024/

7.1 (28,963). Pretty good movie IMHO.

One thing is certain: Blue Ruin's Director Jeremy Saulnier knows guns.

Also see (SPOILERS!):

"The sound of the gunshot got there before the bullet did?" (note "mrhideous")
http://www.imdb.com/title/tt2359024/board/nest/232139883?p=1

"mrhideous" is Jeremy Saulnier (Director)
http://www.imdb.com/user/ur5374786/
http://www.imdb.com/name/nm1099918/

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