The rifle is definitely a Model of 1903. Note the mid-length large-ring action, pear-shaped bolt kno

dead giveaways for the model. Also note the much longer than normal cockin-piece. Turkey bought a raft of these but, apart from a few for South America (Paraguay comes to mind, but evey chance I'm wrong.... operating from memory will do that to you), this mid-length action never became popular. When they were relieved for the 7.92x57 round, there was a clearance channel cut in the top of the receiver ring to acommoate the longer round. As this rifle does not have that cut, I would think likely it still is in the original 7.65x53 calibre.
Bore diameter is .303, groove diameter is .311, so you can check that much with a .303round.
Case body of the 7.65 is almost identical to that of the 7.62 NATO. Why the Yanks didn't just adopt that identical-performance, lower-pressure round is beyond me. Guess they wanted lots of pressure. 'Everybody knows' that high pressure automatically gives you a superior cartridge. Right? Yeah.
Brass is available from Norma and Partizan. Trade-Ex has Partizan in stock at this time. I have heard of people just using fired .308W brass and sizing it; gives you a slightly-short neck which lengthens as it is shot. Ballistically, the cartrige is a rimless .303 and most .303 loads are safe in it.
These rifles all were supposed to have been converted to 7.92x57 in the 1930s, yet this one has NO rework marks and it HAS the Sultan's tughra in place. These were invariably removed during rework.
The receiver-ring legend will be in Turkish but using their modified Arabic script. This also was done away with before the big rebuild program got underway. Likely it will credit DWM with the manufacture of the rifle.
For my money, the rifle is a World War ONE bringback. Who do you know of who was in the Palestine Expeditionary Force of the Imperial Army? That's who brought it back.
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