Thread: my poor 260 (winchester primers do it again)

well was at the range today shooting my new 260 for the 1st time i had to sets of ammo a mates load he have me 20 of which were 44gn win790 behind a 120 coreloct in a Remington case with a fed mag primer.... and i chucked another 20 together last night just so i could have a good go with it they were 36gn (mid way between min and max) of ar2208 behind a 129gn sst rem case and a Winchester standard LR primer

i shot around 15 of the coreloct load it was great accurate enough for a hunting load... so i thought id try the sst 1st 2 were fine in my opinion maybe a little flat but nothing bad (see photo) and the 3rd shot this happened


the shot didn't feel odd no recoil increase or anything no weird noise in-fact it felt completely normal till i looked at the case bolt wasn't hard to open or anything ether
so i really don't think its pressure related and can only put it down to a dodgy primer i have seen that lots have had the same issues with win primers

am i right to think primer? or can someone see anything nasty