Do you clean the primer pockets & if so how? If you have not used a primer pocket uniformer then maybe the little spring behind the firing pin has gone bad. Replace it.
How would peening the face of the breach block help??? What tools does one need?
You misunderstood this. Peening is a BAD thing. Is there peening on the breech block face around the firing pin hole? You do NOT want this to happen. Primers should seat approx. 0.003 below the level of the cartridge head face.
Eliminating that your firing pin hasn't shrank (I hear that happens with fellas your age
) the problem is IMO either:
A. Primer pockets have been uniformed too deep.
B. Seating primers too deep, i.e. "crushing" primers when seating.
C. Firing pin spring gone bad.
D. Firing pin slide loose & causing light hits.
E. You're "limp wristing" it.
P.S. Answer E is a joke.