czech1022-
Your rifle appears to me to be a Mauser Kar98, which was a carbine form of the K98 manufactured between about 1898 and 1905. It was superseded by the Kar98a, with a slightly longer barrel to minimize the muzzle flash that occurred with the Kar98.
The Kar98 and Kar98a were made with the small ring receiver. However, it retained the large-ring threads of the Infantry rifle.
Given the "T" peeking out from the Weaver mount, it is almost certain that the original rifle was made by the factory at Erfurt.
Here's a handy reference:
[color:#0000FF]The Original Kar. 98[/color]--Bob
