First off I've shot 10's of thousands of 22's through custom barrels in rifle competitions and checked barrels with a borescope. Never see leading or funky looking grooves.
So, with a new Hunter upper from Volquartsen this pic is the leade. Reason I borescoped it was couldn't get clean patches. Used bronze brushes and patches. Kept coming out Grey. The train track looking abnormalities go the entire circumference. All but one land has a burr. You can see the burr at 3 o'clock position bottom ofl land. You'll never shoot that out with 22lr. I have 4 uppers from Volquartsen and none look like this one. Yeah I checked them after t seeing this.
Waiting to hear back from Volquartsen as to what they might do.
Edit 4 Dec 24...Volquartsen is replacing it!
So, with a new Hunter upper from Volquartsen this pic is the leade. Reason I borescoped it was couldn't get clean patches. Used bronze brushes and patches. Kept coming out Grey. The train track looking abnormalities go the entire circumference. All but one land has a burr. You can see the burr at 3 o'clock position bottom ofl land. You'll never shoot that out with 22lr. I have 4 uppers from Volquartsen and none look like this one. Yeah I checked them after t seeing this.
Waiting to hear back from Volquartsen as to what they might do.
Edit 4 Dec 24...Volquartsen is replacing it!