The .303 Martini-Enfield has been widely copied by the arts & crafts gunmakers of the Hindu Kush.
The copies outnumber the real ones and aren't safe to shoot---I saw photos of one of their .303 handgun versions last month. Better learn to write with your left hand before you take it to the range
The real ones have original British service marks and dates on the
right side of the receiver---from their time as .450 Martini rifles of carbines.
The real ones also have conversion marks and dates on the
left side of the receiver---and as of last month, the tourist junk fakes had not caught on to that. Post photos here if you are in doubt.
Even if it's real, they were usually worked hard and received ever worsening care as they were bumped down from first line service to an ignominious fate guarding some kraal in Lesotho.
The one in the photo was made in 1875, at LSA and converted at Enfield in 1899. It went to Australia, where cleaning a bore is a known art---so it's in outstanding condition.
I love shooting the old girl.
-----krinko