Ah, looks like you've strayed into one of the dim corners of the Washburn basement.
For the most part, Washburn shows great consistency. Like, Idols look like Idols. Then they start sniffing the lacquer thinner, & Idols appear with Les Paul bodies.
Or their "Billy T" guitars magically become "Maverick" (but at least they keep the same shape). The higher-end models for 1997-2000 get a WM prefix -- from "William," right?
Which gets really confusing when in 2008 they recycle "WM-" to mean "Washburn Metal," which is where YOU walked in.
For 2008-2010, the HM guitars weren't really any sort of "series," but some cool "heavy metal" versions from various lines, like the Idol-bodied WI-50, the Renegade-bodied WM-24V, & the Wavepoint-bodied WV-40, as well as the Nextars -- depending who you talk to, HM also includes the ~2001 WR Series ("Washburn Rocks" -- geddit? geddit?) guitars, a similar hodgepodge (WG-580, CS-780, RS-980) that included the bottom-end WR-120/-150 (precursors to the X-10/-20).
I haven't seen many of these "in the wild." Photos would help, as would the date or at least first three digits of the serial number.
Unfortunately, that's the era that Washburn's catalogue division also began snorting correction fluid, so their catalogue PDFs are multilayered & have been known to lock up my PC, so here ya go.http://www.washburn.com/media/catalogs/
MORE FUN: it's easily possible that the WM-17V was some one-off Guitar Center model or something, & never appeared in ANY retal catalogue.
(FWIW, my notes say the WM-24 does appear in the 2009 catalogue.)