Green’s Dictionary of Slang

to shoot badly at birds so as to wound rather than actually kill them; such a shooter is a tailor.

1873		G.W. Hely-Hutchinson Reminiscences of the Lews 168: I have often asked myself, ’Were you a tailor or not, for shooting that tame stag?’ [Ibid.] 98: I once winged a grouse, which ran towards a burn, and as Tom was retrieving it, I tailored another in the same fashion, who also made for the same burn.
1889		Blackwood’s Mag. CXLVI 475: They ought to wait when a bird rises in this manner and tailor him accordingly .
1903		Westminster Gaz. 29 Sept. 4/2: One of them [...] letting birds past him untouched, knocking out tail feathers, and generally ‘tailoring’ his pheasants .