Brass dust in the firing pin hole?

Petrov

Sergeant
Full Member
Minuteman
Oct 3, 2009
521
298
41
Western NY
So I have a remington 700 rifle on it's 2nd barrel. 308 Win I shoot the snot out of it and the cam surface on the bolt handle has been worn off quite a bit if that is relevant.
Lots of clearance between the firing pin hole and the firing pin and I always get cratering even with mils load.
Me and m friend were doing some shooting and we took a break because it was so beautiful out we just sat down and soaked up the sun.
I tool this break time to inspect my bolt and I noticed something strange, my firing pin was sitting in a brass "sleeve" inside the bolt.
I went and got a dental pick and started picking at this sleeve and it turns out to be really fine and compacted fine brass dust that kinda compacted/sintered into a sleeve inside the firing pin hole.
is this normal? What could cause This?
The bolt had about 250 rounds since last cleaning and it wasn't there last cleaning.