John: How was the accuracy of your 'carbine'? Do your fired cases appear overly stretched in the Head area?

IMHO - Since your carbine appears to have a more generous chamber than your model 1898 rifle, You should relegate those fired cases to future use in your carbine and neck size only (to avoid needless over-working of the brass). Simply back-off your resizing Die a turn or two.

I find that most Model 1898 Krags are pretty tolerant and will feed a good variety of bullet weights and shapes. Over-All-Cartridge-Length seems important to Krag cartridge feed. Bullets should be seated out as far as practical, allowing for sufficient neck-tension and function through the magazine. The bullet nose contacting the magazine 'feed ramp' helps with directing the loaded round into the chamber.

Many magazine feed problems seem related to dirt, gunk, and dried grease in the feed path or carrier/follower arm assembly. Thorough cleaning and light lubrication resolves this. Another  possibility is a damaged (dented) or wrong (model 1896) side-plate on a model 1898 Krag.

I am attaching a picture, showing how, the follower/carrier extends out of the side of a Model 1898/99 Krag, with the side-plate removed. It also shows the Gate Hinge-Pin, rotated, to expose cam & spring tip for lubricating. You can always try your rifle's side-plate on your carbine to see if it solves the problem.

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