Here are a couple of spent brass from my 15-22. I do believe they look as though they have a much better firing pin impact than do those in your photos.
So....first question.....was it cold out today? I ask only because cold temps can cause some lubricants to get thick....and this could cause a weak firing pins strikes if the firing pin is sluggish.
Before I did anything, I would give it another good cleaning and NOT lube the anything to do with the firing pin, hammer, etc. I would leave the fire control group dry for now....and then take it out to see how it works.
Hopefully other will have some more ideas.
Good luck....you've done some good troubleshooting so far.