M17 refers to Millennium 17 - Historical Miniatures Game Convention 2014, which is located this year in Round Rock, TX. It's a three day convention with all kinds of historical miniature games. Like Bolt Action, Saga, DBA 2.2, Flames of War... and (mostly) other games revolving around historical battles and events. It also has vendors selling all sorts of miniatures (mostly historical) and a swap meet on Sunday where people set up tables and sell all sorts of gaming stuff for cash. Last year I picked up a Viking 15mm FOGAM army for a good price. They might even have some old Warhammer stuff... you never know what a swap meet will bring!