Dilly541,
A common bullet for the 7x57R and 7x65R both is the 173 grain H-Mantel, so your rifle will stabilize anything up to that length. When loading for my 7x57R I found that anything lighter than 160 grains wouldn't give me a POI useable with Brennekes( 16ga-67 1/2mm). Due to the fast twist, the lighter bullets usually hit high and right. Also the throat was pretty long for light bullets( as I recall I tried down to 120 gr). However, just like every other rifle, you won't know until you try.
Mike
