1994 1p with reeded edge on half of rim

[coinclueless]

So I'd like to know if anyone can tell me anything about this 1p I found a couple of years ago when I was cashing in a large savings bottle at a Coinstar machine it was all 1ps and 2ps, some from a cafe business, so I know it's been in general circulation. The machine actually rejected this one. It's got a shiny copper ring with fine ridging around part of the edge, like a 5p's reeded edge, but it's flush on one side and stops short on the other rather than going all the way round. I can't find much online about this kind of thing or coin misprints generally, so any info would be appreciated, thanks