You really have to slug your barrel. The Finns are .308, I have not had any problem using 303 enfield bullets in my Russian MN's. In fact after slugging 2 and finding the bores between .311-.312, I dindn't bother to slug my newest one and just use the .311 bullets. I really like to use the 125 gr sp's designed for the 7.62x39 in my m44. I load them to about 27000fps for a real nice low recoil load, I also like to use cast bullets sized.313 in it.