The following information on the Turkish Mauser Model 87 comes from Chapter 10 of Mauser Rifles and Pistols by W. H. B. Smith. Mauser Rifles and Pistols is also available to purchase in print.
After intensive experimentation and observation Mauser had found that the best ballistics could be obtained, with the black powder then used, by reducing the caliber to 9.5 mm.
This new rifle with improved locking lugs was offered for Turkish tests. In 1887 Turkey gave an order through Ludwig Loewe & Company of Berlin for 500,000 rifles and 50,000 carbines of this caliber and design—Mauser and Loewe being 50-50 partners in the order.
This rifle was 49.5 inches overall and weighed 9.37 lbs. The barrel was rifled with 4-grooves to the right. Sights were ranged from 200 to 1600 meters. Bore diameter .374. Groove depth .0059.
The cartridge measured 2.47 inches overall and weighed 555.5 gr. The case was 2.34 inches long and weighed 194.46 gr. Bullet length was 1.047 inches, weight 284.9 gr., hardened lead. Diameter .382.
The 1887 Turkish is very seldom encountered, as the cartridge for it was in manufacture for only a short period, and obsoleted rifles were widely destroyed by the authorities.