I am going to go ahead and say no this is not a clipped planchet it appears to me to be PMD but I'm going to ask the group ya'lls opinion. I don't see a Blaksley effect, I see upset of the rim from possibly a file and there are many "clips". 5 to be exact along the rim which makes me think at some point someone was trying to save some silver, I however have read that not all clipped have a Blaksley effect.
I don't think that it's a clip. The angle of the arcs there don't fit with a half dollar, but hard to tell without measure.
It doesn’t look like it but it also looks like a reeded edge as the clips as do small and that could be one. I think it’s impossible to have 5 clips. Three clips are the most I know of as shown on the chart below. Here’s one that I own. It easy to see on mine as the copper edge is present inside of the clip.
On a true Incomplete Planchet if it is very small you won't really see the Blakesley Effect. But your coin is not an Incomplete Planchet. It is altered post mint IMHO
As I suspected, PMD. I've heard that clips sometimes don't have the Blaksley effect that's why I wanted to ask.