I've had similar probs with my B-28,...but in useing a little "know-how" with a dremil tool,.. and some patients,...things smoothed out real well . Plus I just plain shot the living crap out of it! ,....No Mercy!!!!!!!!! Took a while,....but she's a well behaved Mama San Now. Can't decide if I like going with the glass, or going with the irons!?!?!?!?!? As for the spring rub,...Mine did too every 50 rounds or so,..it (the spring) would 'cycle' around and make the most God-Aweful popping sound,....but this too has passed. Like I said,...No Mercy!!!! I plan on sending mine back to Mike for a check-up,....after about 10K more rounds!!!!! LLH!!!! tjk
PS If you send it back to Mike,..he will make it right!!!! No BS, Thomas