Holy smokes a Mauser post! well,,, as an 1891 Argentine Mauser owner (7.65 x 54). parts and accessory's are on gunbroker.com, and even ebay have stripper clips.
This website has them for .50 cents a piece:
http://www.sarcoinc.com/m98.htmlPart # STC018, its about the 9th or 10th one down on the list.


(sorry can't help but post a pic or two of the old girl), she'll keep up with any .308 and shoot better than my eyes can keep up with.
Grandfather sporterized it after WWII, and it will rock and roll.
Good Luck with your 7x57. The NRA published the text in the photo, great story of the Mauser Bros.
Many rifles to this day still base their action on the Mauser Bolt.

Tom W.