It is hard to trump seeing a Krag serial number, first hand, and being able to adjust lighting and to use magnification.

So ... #28828 it is!

(Photos often fool the eye).

"SRS" stands for Springfield Research Services. It was data collected and published, in a series of volumes, by the late Franklin Mallory (with some assistance from others).

The 'data' collected was mention of U. S. service arms by model and serial number in official documents.

Frank Mallory put his Krag serial number findings in the Appendix of "The Krag Rifle Story", second edition.