Crunchy bolt wolverine 2

Hi all,

my wolverine 2 started making some funny crunchy noises when I would cock the bolt this afternoon. It slides back and forth without resistance, it’s the last 1/4” or so of pull that it would make the noise. It’s still working fine, but I’m wondering what has changed to make it do this. 

The rifle has about 2k rounds through it. I was shooting off a bench from my garage, so I don’t think any crud would have gotten in.

any help appreciated, thank you.

Ryan