Read a Few Days Ago: Gun Work by David Schow, 2008, 9780843959673.
Pretty decent. A good pulp style paperback. If Schow isn't a gun nerd he does a good job of faking it.
Former soldier Barney gets a panicky call from Iraq pal Carl. Carl is in Mexico City and asking for Barney's help in rescuing Carl's kidnapped wife. Barney travels down to help and take over from the incompetent Carl. Barney is a gunman and there are hints to past gunwork.
A gunman is all Barney is. He works and sometimes sleeps at a Los Angeles gun shop and range, hangs out with gun guys, leases a mostly empty apartment, and drops his girlfriends once they start getting too close. (I suppose Carl has a bit of a PTSD issue.) People think of Barney as the guy to call if they need extra-legal help. Barney is not a spy or hired shooter but he doesn't dissuade people from the idea.
Barney is very competent though. His service training, combat experience, and continued training and practice make him a good guy to call. Barney takes pride in this and it ends up being his initial donwfall. After a botched pay-off for Carl's wife Carl and Barney are captured at their hotel. Barney is held prisoner, figures out that Carl conned him the whole time, is viciously and repeatedly beaten and tortured, has his index fingers cut off, and is ultimately thrown in a polluted river and shot in the back several times. Barney floats downstream, is rescued by a Mexican jeweler, recuperates a little, survives an assassination attempt, then makes his way back to the U.S. with the help of some Mexican wrestlers.
Barney gets his gunner friends to team up for revenge against Carl and the kidnapping gang that tortured Barney. Shoot-outs ensue in Mexico City. Barney and pals are hunted in L.A. by the kidnapper ring. Barney finds the honcho and Carl's evil ex-wife. Barney moves to Mexico to live with his only friend, the Mexican jeweler.
Lots of gun action, despicable bad guy action, femme fatale action, noble Mexican action, noir loner action, SIG love action, .357 SIG action, all my friends are dead action, hot-but-evil-redhead action.