I own a mosin Nagant M-39 Sako stamped. Cost me 80 bucks 10 years ago. Made my own scope mount, cheek rest , muzzle brake, free floated the barrel. The best 7.62 54 r ammo i have ever fired was norma 180 gr. sp. not cheap but the last outing the last 3 shot group was 1 & 1/16 inch group. this rifle realy likes 180 gr. ammo. about the blown primers, don't shoot any more of same ammo, have headspace on rifle checked, check for correct overakll cart. length. dangerous to shoot may blow your face off. sorry about message, am new guy on computers. old men are tough to teach new tricks Tom Diet.