This is pretty interesting. If your gun was issued to an infantry unit it was most likely a rifle and not a carbine. 1899 was a little late for the Cuban affray but right there for the Philippines. The 4thy US Volunteer Infantry is not to be confused with the US 4th Infantry Regiment, which was RA.

The 4th Infantry and the 4th Cavalry both served in the Spanish American War and subsequent conflicts. I'm having trouble finding any traces of the 4th USV, which was formed up during the Civil War, but kind of drops from sight later on. It may be a misprint in the SRS records.

jn