Like AC/DC, Motörhead rarely stray from their niche, crafting reliable records from a punk metal template that began in 1977 with their self-titled debut. Inferno is no exception, as the sum of its parts does little to deviate from the formula. Opening with the blistering “Terminal Show” — marking the first of two appearances by guitar legend Steve Vai — Lemmy, Philip, and Mikkey burn through 12 raucous blues-rock fist-pumpers with the energy of a trio of wily twentysomethings. Lemmy’s gruff vocal style is ageless; as “f*ck you” now as it was on “Ace of Spades.” All of the classic Motörhead themes are present; there’s sticking-it-to-the-man (“Life’s a Bitch”), murder and death (“Smiling Like a Killer”), and sex (the surprise back porch acoustic jam “Whorehouse Blues”). For a band as seasoned as Motörhead, churning out the same record over and over again isn’t that big of a deal, as their skillful execution is more than equal to the material, but it would be cool to introduce a dark horse now and then. Inferno won’t win over any new fans, but the group’s legions of supporters will happily pick out their four or five favorite tracks and wait for the next installment.