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Have a Gunsmith take a look at your rifle to confirm the calibre. Some of these Schmidt Rubin rifles were modified to shoot the 30-30 Winchester cartridge by Globe Firearms, back about the 1970s. If your rifle is marked "30-30", then it is likely that your rifle is one of these conversions.
DO NOT attempt to fire the more modern GP-11 Swiss 7.5x55 ammunition in the older 1889 Schmidt Rubin rifles. It is too powerful for the action, and was designed for the 96/11, G-11, K-11 and the K-31 rifles.
It does help, when asking for information on a rifle or anything, to give the most information you can, and include pictures. Since there was five major variations of the Swiss rifles of this period, without more details, an accurate answer can not be made.
Also, the Internet can be your friend in a lot of cases. If you "Google" the name "Schmidt Rubin", you can find a lot of information available.