My buddy and I were firing his 7.62 x 54R on the weekend along with others. And he bought some FMJ ammo at gun show on Saturday C/W feed clip. I fired two shots no problem third went to eject and bolt will only come up part way. Cannot eject shell. I am figuring shell expanded and jammed. Can I just slide a rod down barrel and gently tap shell from the barrel side while trying to open bolt with out causing any damage? Any help would be appreciated.