heres some at cheaperthandirt

http://www.cheaperthandirt.com/8x57maus_cid.htm

A Brief history of the Gew88

1888: New Bolt action smokeless cartridge rifle adopted by Imperial Germany. Bore diameter, .311, Groove diameter .318. Bullet diameter .318 Bullet was long and cylindrical. Cartridge called "Patrone 7,9mm J" (Infanterie in Fractur script)

Early trials found that the excessive friction of the long cylindrical bullet and identical Bullet-Bore dimensions led to increase risk of split barrels and also excessive metal fouling. Rifling Grooves deepened to .321. This was noted by marking the Barrels "Z" (for "Zuge" meaning modified rifling); at the same time, new steel was adopted for the receiver and barrel ("nm" mark "neue materiel" )

In 1903-04, the new "S" Patrone (Spitzer, .323 Bullet) was introduced, and the Bore of the new barrels for the Gew98 was fitted with .322-323 Grooves. The Spitzer Bullet had less bearing surface (about 35% of that of the M88 Cylindrical round nose).

In 1905, a major program of converting existing stocks of M88 rifles to use the new "S" Patrone was undertaken ( as mentioned above.)

In 1916-17, Germany supplied large quantities of Gew.88/05 to Turkey as Military Aid. These used ammo common to the gew98s that Turkey was also given.

By the 1930s, Turkey was beginning to rebuilt its entire arsenal of Mausers to take the German "S" Patrone 7,9mm;

The gew88/05 in stock began to be converted, either by fitting new barrels, and otherwise leaving them as "Commission rifles" or rebuilding them completely to the M1903/30 style, with NO barrel Jacket, and the standard Turkish woodwork and bands. The new Barrels were proper .323 groove barrels.

Advice for use of any Gew88 type rifle, refurbished or not. As the receivers are older than 1897 (100 plus years) and built in the early years of smokeless powder development, they are not suitable for the heavy loadings of 1930-1960s 7,9mm Military ammo. Use only US Commercial so-called "8mm Mauser" ammo (it is under-loaded, and has a .321 projectile to boot), or handload with either .321 or Cast lead bullets with reduced loads.

Turkish rebarrel jobs (marked "7,91" on the barrel, usually underneath) will use .323 Bullets, but why bother. Treat the old ladies with care and consideration, given their advanced age.

Good shooting and collecting.

Regards, Doc AV