The Gun Men series
If this was going to be the last day alive, he wanted to see every bit of it! 

When you make your living by the gun, it's only a matter of time before your past catches up with you.

Sloan has faced Lucas before, but this time it's not just his life on the line. This time, six innocent families will also pay the ultimate price.
Book 2: Gun Work
After spotting his own obituary in an Albuquerque newspaper, gunfighter Sloan strikes off for Carrabelle, near the Mexican border, to find out what's behind the notice and who was slain while borrowing his name. Upon arrival, mysteries abound: Why did a group of Pinkerton detectives kill the "Sloan" whose death attracted notice in the press, and why are they still loitering in Carrabelle two weeks later? Was the obituary a trap, or a simple mistake? What relationship, if any, links Sloan to the dead man buried under his name on Boot Hill? Is a corrupt lawman involved in the confusing plot? Who will survive as Sloan unravels the conspiracy? And if he learns the truth, will he be launched into another one-man war against all odds?

Book 3
Book 4
After his brush with death in New Mexico Territory, Sloan carries the fight back to Texas and the wealthy, vengeance-hungry rancher who put Pinkerton guns on his trail to settle an old score. It's a long ride to face an enemy he's never met, backed by more Pinkertons, dodgy lawmen, and a small army of gun hands pledged to defend their master. It may be Sloan's last fight. The bad news for his adversaries is that he's got nothing left to lose.

When mixed-race homesteaders help gunfighter Sloan recover from a nearly-fatal wound, he repays the favor by defending their settlement against a rapacious would-be land baron.

In the process, he must face Pinkerton gunmen, a Texas Ranger far from home, and his own mortality.
Book 5
Book 6

A wealthy businessman hires Sloan to track down serial killer and sexual sadist, Ossian Sweet, who murdered his daughter where sworn lawmen and Pinkerton detectives failed.

Prior conflicts with the Pinkertons mark Sloan as a secondary target while they seek to avenge murdered colleagues. Mafiosi from New Orleans join in hunting down the killer, who claimed one of their own.