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Make sure that the fine rivet, that holds the follower to the carrier-arm, is totally flush and not sticking out a bit and dragging.

There were changes to the follower and carrier-arm during model...

FWIW: On reviewing much of this thread. I believe it is possible, the 'extractor-notch' of the OP's Criterion barrel may be interfering a bit with the 'claw' of the extractor.

Metal interfering...

What make of Brass is your 'test round'? Is it a factory load or a reload?

Have you tried a different assembled Bolt in this project re-barreled Krag?

(This thread has gotten rather long,...

The front edge of your bolt-face 'flange' may be making contact with the barrel's breech area.

'Flange' contact would create resistance and stickiness to rotating a stripped bolt fully closed (or...

I have not 'tinkered' with a Criterion barrel, yet.

The rear sight model, that you are going to use, might dictate your best approach.

Some of the Krag sight screws would be easier to...