A light-weight grease like TW25B is nice for this. After this place is thoroughly greased it's good for thousands of cycles. Concerning the effects of rounded rifling on accuracy, the rifling provides an angular velocity to some bullet so working with abrasives close to the muzzle will generate imperfections https://telc92356.blogsvila.com/36209323/the-smart-trick-of-telc考试报名-that-nobody-is-discussing