Many years ago I examined and took photographs of a Barrel with incredible damage to the bore which I had never seen the like of before. I still have some sections of that barrel.
Quite a discussion resulted on the OzFclass forum.
For a while my (and DaveMc's) reports were on the web but may now have evaporated so I am collecting here some of these reports. Unfortunately I cannot find all my material and I see that one is actually a 'Draft'.
But it may still be of use to anyone who has not seen this material before.
I will add that I have now used two 7mm Bartlein 5R barrels with truly excellent results. One shot a record number of Xs at last years NQRA shoot. I also have some Madcos which are also excellent.
The barrel 'featured' here was not mine and seems entirely the result of inappropriate cleaning.
I have noticed that it takes very little force to stop a cleaning rod from turning in a 5R barrel and, in conjunction with an abrasive and bristles, was undoubtedly the cause of what happened to this barrel.
People used to cleaning 'normal' barrels should be very wary of this if they get a 5R barrel.
Download the two pdf files below and 'enjoy'. OR maybe shudder.