Is the barrel roll-marked for the 10/17, or just the caliber, and are we talking HMR or HM2?
Ruger did make quite a few 96/17Ms with .17HMR barrels, so if it's a dual extractor cut HMR barrel it may be off one of those. I used one on one of my 10/22Ms before I bought the Volquartsen HMR.