Green’s Dictionary of Slang

(UK Black/gang) a stainless steel gun.

2013		Stix & M. Dargg ‘It’s Cracking’ 🎵 Me and mayniss with the stainless / You wanna see what happened.
2018		Unknown T ‘Mad about Bars’ 🎵 Word, man, rock on my stainless tucke / We don't do this monkey bar ting.