Green’s Dictionary of Slang

echoic of the sound of an object hitting or being hit suddenly.

1835		W. Otter Hist. of My Own Times (1995) 81: I let him have a slash of lime from my brush bip into his eyes.
1941		G. Kersh They Die with Their Boots Clean 3: Poor old Muddy gets one, bip, right in the forehead.