Here goes........
The first photo shows the miss-feed. The bolt has lost control of the cartridge because the feed angle has become too great.
The next photo shows my three M98's lined up, and a pin punch indicating the area I'm talking about on the Gewehr 98 receiver, which is on top.
So those little shelves which sit on either side of the receiver (near the feed ramp) serve a very important purpose it turns out!
So I just learned something new about these old rifles. Next time I'm at the range I'll have to come up with a system to manipulate the bolt in a way that doesn't cause feeding issues. That will be the next challenge.