Primers Flattening in the pocket.
 

I have a remmi 700, shooting 220 SMK, LC 07 brass, Nato Primers. The primers in the last batch of ammo I shot flattened out inside the primer pocket. You know the little trench that is between the top of the brass filled in with the primer cup. Also the firing pin strike is VERY DEEP. But the primer has not actually backd out . This is very straange. Anyone else ever had this happen???

The beginning signs of excessive pressure. Back off .5 grains on your load and see if it goes away.

I was originally shooting 220's /7.5gr unique . about 1079-1050. bullet in the rifling. so I went to 7.6 gr unique and made 10 rnd batches seating progressivly deeper, this is when the primers started acting like that!

+ 1 on excessive pres. With Nato primers flattening out you are knocking on pierced primers door! Question - Was the 7.5 into the lands not accurate enough the reason you started changing? My TC loves them loaded as far out as they will go...Just wondering......