This is something I picked up off another non UK site.
"Just thought some might like to see a few pics of the Blaser 93 , sorry to say that its NOT complete , but it shows the important bits like the bolt and locking splines etc .
This is just pics of one incident , as far as I know there has been at least 3 , may be more , I just know enough to steer WELL clear of it .
There are far better designed and made rifles to EVER bother with this , just NOT worth IT ."
I beleive that they are caused by a primer being pierced , and the gas flowing back and melting a plastic disc that cams the locking fingers/splines into battery , then the bolt unlocks REAL quick , into your face .
Are you sure you still want a Blaser?