Green’s Dictionary of Slang

1. (US) a recidivist.

1865		N.Y. Times 21 Aug. 3/3: Margaret Burns, a regular revolver, one who is no sooner out of prison than she finds her way back again.
1891		J.A. Riis How the Other Half Lives 73: ‘Revolvers’ all but one. Good for six months on the island, the whole lot.
1909		I.L. Nascher Wretches of Povertyville 194: Most of them are rounders or ‘revolvers’ – that is, wretches who are repeatedly sent to the workhouse on the charge of drunk and disorderly.
1931		Irwin Amer. Tramp and Und. Sl. 158: Revolver.–See ‘repeater.’.

2. (US tramp) a veteran tramp or criminal.

1870		Appleton’s Journal (N.Y.) 22 Oct. 490/2: A little ‘revolver’ who hopes to get quarters for nothing in a lodging-house.
1899		J. Flynt Tramping with Tramps 386: ‘Revolver,’ or ‘repeater,’ is both a tramp and a criminal term for the professional offender, the man who is continually being brought up for trial.
1921		P. & T. Casey Gay-cat 304: Repeater, or Revolver—an old-time or professional tramp; a ‘blowed-in-the-glass’ hobo.