Reloading problem

[Motard]

@ Petnyg: Blaser have the bad habit to misfire if the bolt is not steady pusched on on closing. That is for the shooter safeness but is often perceived as one issue or a misfire. As you said there is a small mark on primer face this could not be the case because the pin doesnt move althought the triggers clicks. Nevertheless cause is rather impossible to judge by eyes if the blaser bolt had reached the full end of his run try using a bit more "smash" and check if the problem persists. On the other hand after having a Rem 700 gone self off on closing the bolt I always care about having the primer with a minimum recess in the brass pocket (not flushed). In case a second passage trhou the RCB tool is the cure but you mast be very carefull about risks of a detonation. Otherwise one drop of oil on the primer anvil will render it definetely harmless.

 

[TimWest308]

Set your die so you’re getting 0.002” shoulder bump. Have you tried a different primer?

 

[MTheaded but happy]

Primers require percussion to detonate . If you're sizing the brass hard , it allows the cartridge to effectively ride the strike . Hornady had a batch of 223 ammo that suffered the same issue a few years back . Firing pin protrusion is generally around 0.060" but it needs to be able to impact rather than push .
Be aware , if you're sizing the brass excessively, you'll likely shorten the life of your brass . Keep an eye out for incipient case separation .
As others have pointed out , keep the shoulder bump to a minimum . No more than 0.002" and giving the bolt a strip , clean and light lube certainly won't do any harm .