Your Turk K'kale is a Newly made (at Kirrikale factory) Turkish Mauser Rifle, variously described as a "Tufeki M938" (by Turkish Manuals,) but the Turks lumped ALL 7,9mm calibre "Mauser" rifles into the "M938" description...the "938 (Aka 1938) signified either the commencement of operations of the Factory at Kirikkale ( outer village/suburb of Ankara), or to commemorate the Death of Kemal Ataturk, who died in 1938. He had been responsible for the Policy of standardization of all Turkish Rifles to 7,9mm, as well as organising with ZB of Brno, the installation of manufacturing capacity within Turkey, so as to be self-sufficient in Rifle production. (From 1923 to 1938)
The "Kirikkale Mausers were designed to be typically Turkish, whilst using the Czech/German Vz98/22 as a design start point, with one difference...the thread diameter of the barrel...was a "Small Shank" (.980"), the same as the M90, M93 and M1903 Turkish Mausers, and also the Gew88/05 Commission Rifles already in Turkish Inventory...making the manufacture of replacemenbt barrels easier...Only the Vz98/22 and the WW I Gew98s retained their original "Large shank" ( 1,010" ) barrels.
Bolts, Trigger. sights and Triggerguard parts were all interchangeable with the Gew98 and the Vz98/22 rifles. Stocks were made on the M1903 Pattern, with small adjustm,ents for receiver profile, etc., so that a common Bayonet and bands could be used on all "Models" of 7,9mm rifles, of whatever original construction.
First Pre-production runs (Machinery trials) began in 1939; and there are "Kirikkale" marked rifles with 1939 dates....(and Not on my Parallax Survey of Turkish Serial Numbers).
At the time, the serialling system was not finalised, and so the First batches of rifgles were serialled on the rear bridge(like the earlier M90, M93 and M03 refurbishments...and in 1940, it was decided (from my observations of surveyed and personal serial numbers) to switch to a separate serial series, and stamp these in the normal ( on Receiver ring) place foir serial numbers. Thus the early 39 and early 1940 made rifles will have "double" serialling.
The "Number" for survey purposes is the Left receiver/Rear sight/Barrel number;
As in many Turkish rifles, barrels/rear sights are mismatched to receivers (it seems Turk armourers considered both barrels and receivers "non-fixed" parts, seeing as so many mixed matches are found between these two major parts....)
The appearance of the letter "B" on many Turk Kirikkale Rifle Parts signifies that these parts have been made by the Kirikkale Factory, and not "scrounged" from Gew98 or Vz98/22, or even earlier Turkish Mausers.It is also a quick indication that say, the Bolt is NOT compatible with a '903 or '93 Marked receiver (bolts here of intermediate Mauser Length, rather than the standard length M98 Bolt, which the K'Kale uses.
Crescent moons denote Turkish Property (both Ottoman and Republic), so small parts such as screws could be either Pre WW I or Post 1938...Mauser screws being basically interchangeable throughout the M93, 03 etc series.
The 13xxx number fits in my survey for Early 1940 production, and it seems the rifle may still be Matching, to a degree...the barrel and rear sight parts marked "9069" match the receiver ( also bridge marked 9069) whilst some other parts are mixed.
Stocks were made of what suitable wood was available... Turkey supplied a lot of Circassian Walnut (a variety, not a region) to other countries for gunstock manufacture, as well as its own; but experience with other timbers after WW I would account to the use of Birch/Beech/ other types of Timber more readily available to the Gun trade.
In any case, Turk Gunstocks are always well matured and made, even if the use during many years of "peacetime" training can leave the condition a bit poor.
A stock-standard 1940-46 Kirikkale Product (my survey estimates at least 250,000 rifles of this model were manufactured from new in this period, along with about 15,000 K'kale "Short rifles" (1944-46); not bad going, in the middle of WW II, essentially cut off from the rest of the neutral world, in between two big belligerants (the German Axis to the North, the Allies to the south, and Russia to the East. As well, the ASFA (Askeri Fabrikalar, or Military Factories Administration) continued converting and refurbishing Gew98s, Gew88s, and M1903s to the unified format adopted in 1929/30, for unification on 7,9mm ammuntion.