Dear Mr. Hicks,
Thank you for posting your request on History Hub!
We searched the National Archives Catalog and located two series titled Reports on Powder Tests , 3/1877 - 1908 and Reports Relating to Tests of Ordnance, Routine Work, and Other Matters, 1/1863 - 12/1908 in the Records of the Office of the Chief of Ordnance (Record Group 156) that include information about Sharps Rifle. For access to these records, please contact the National Archives at Boston (RE-BO) via email at firstname.lastname@example.org.
We also suggest that you review these websites for information about Sharps Rifle:
We hope this is helpful. Best of luck with your research!