Shapes

[5MadFarmers]

Meh, I recovered an old copy of my board to pin that side plate change you mention. That is specifically an 1896 model change. The plates with the screws at the crease (1892s) is model 1892 only. Late 1892s have early 1896 parts though so it gets murky.

1896 Mar 10: Thickness of upper half increased and cartridge rib lengthened.

The change to the side plate. Listed with all of the 1892->1896 changes.

The other visible different I mentioned:

1899 May 5: Rear upper corner rounded.

The barrel/receiver fillet was done in July of 1899.

Fun with parts.

[Alfred]

The fracture thing is a logical assumption on my part. They encountered fractures in 90' angles repeatedly. Not just on the Krags. The early extractors on the Krags have a 90' angle which received a fillet. The early strikers ditto. The magazine gate pin head also. Half a century later they encountered that on the operating rods on the M1 Garands. "Race track cut" to round it. Strange how they'd run into something like that yet repeat the mistake again.

Even FN with all its expertise manufactured many Mauser bolts that did not have the prescribed radius to the locking lugs where they met the bolt body.
one leg of the Left hand lugs occasionally fractured.
Owners took to installing surplus K98 bolts.