Macklin's Women (Gunsmith Series #1) by J. R. Roberts
Ex-lawman Clint Adams makes his living as a traveling gun trader, a job which takes him all over the West. In a sleepy Missouri town he finds a trio of beautiful women who will do anything--pay any price--to be reunited with their former "protector," Con Macklin.
The Gunsmith agrees to take them to him and rides out on the dirty and dangerous trail to Mexico. He delivers the women but faces an army of hardcases led by Macklin--who wants his women back and The Gunsmith dead.