Hi i bought this new last week and when firing it was making a strange bang when firing after three shots, it fired thirty seven factory bullet shots over three outings twenty sako nosler bt and seventeen hornady v max .It was sent back to gunmark today .I had a picture taken of the bore and it looks like there is a crack also looks a bit rough .The bullets when ejected looked like i was getting gases coming back the way they were covered in a grey like looking mist.Any ideas guys

