They're not saying goodbye, they're simply looking back at the past three decades - both their own work and extensive covers - and looking ahead to what is to come.
This two-disc collection features 10 of their biggest singles to come out since 1989's debut album Taking On The World and a second disc of 10 of their popular covers including Cameo's hit Word Up which previously earned Gun the MTV Europe Music Award for Best Cover.
And while there's plenty of nostalgia here, the sheer one-track nature of Gun's 'dad rock' vibe makes much of the collection so-so. We are stuck between one load of songs that feel at home on the Planet Rock repeat playlist, and others that veer more into commercial radio territory such as the unashamedly pop leanings of Break The Silence with its sing-along chorus and electronic encasing of the rock sound.
It's one of those listens where nothing is particularly bad, but nothing really runs away with the imagination anyway. Especially given the band's name you expect a bit more...fire and passion or just oomph.
The stripped back Higher Ground that eventually erupts into a screeching guitar-fest is a bit more attention grabbing if a tad dreary, and there's some bite to the thumping percussion in the high-octane Steal Your Fire - probably the best single on offer here.
There's more entertaining listens in the covers section.
Their cover of (You Gotta) Fight For Your Right (To Party) by Beastie Boys is a little too similar to the original to warrant being done again, but they do some great work elsewhere.
This writer had never considered that Hot Chocolate's Every 1's A Winner would sound this good as a rock track with a tantalising melody. And Blondie's Union City Blue sounds good too with that famous Word Up cover still sounding fab.
If it were possible to just buy the 'covers' disc then it might be more popular. The originals just sadly sit too firmly in 'dad rock' to appeal to many more.
Gun play alongside Dan Reed Network and FM at Wolverhampton's KK's Steelmill on December 13 as part of The Big 3-0 joint anniversary tour