The scaling on the surface is odd, and the cut is much wider than the springs I have inspected.
Possibly, the alloy is different from that used in the original springs, and the cut is wider and deeper in order to compensate. Most of those you find after an image Google search on "luger locking bolt spring" have a narrower cut which is off center.
Here's an example:
https://image.sportsmansguide.com/ad...6/60725_ts.jpg
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Igitur si vis pacem, para bellum -
- Therefore if you want peace, prepare for war.