My best guess is the ammo.
Could be.

Since you have the Axis style firing pin and spring assembly you might also read some of the recent Axis post discussing light primer strikes.
Had issues this weekend with my Savage Axis 223. Never had any problem with failure to fire before this.

Ammunition Frontier 55gr FMJ. None would fire. All 20 rounds failed to fire.
Ammunition Winchester 55gr SP. All 20 rounds fired.