Something I learned last week. Ever since owning my AI, I have never thought about lubing the back of the firing pin assembly. I did so because my bolt was significantly heavier on open and especially closed ever since getting it cerakoted. Little did I realize it was because the factory grease had been taken off by degreasing, sand blasting, and cerakoting. I greased it up and it feels better than it ever has. Everywhere that is circled in blue. A little goes a long way if you use the right grease.
Also grease the rear face of the bolt body where it meets the front side of the bolt shroud.
View attachment 7882281