As has been said, you have the WRONG AMMO.
Below are two rounds. On the left, 7.62x54 Rimmed. This is for the bolt action Moisin/ Nagant rifle. The OTHER is 7.62x39. Shorter, no rim, much less powerful, and intended for the SKS and the AK-47 rifle.
This is NOT a slam- we need all the gun owners we can get- and we cannot afford to lose any of them. Lack of knowledge here can get you hurt. You REALLY need some hands-on guidance from an experienced shooter or gunsmith. There may be some of us in the area where you are. Talk to us, and reach out, my brother.