Fromhttp://www.network54.com/Forum/79537/message/1328049471/Brass+screw+and+lapping+compound+re-crown-+How+was+your+luck-

I dd some tests today at 10m.

Total group size..10 shots was 1/4" so about 0.03 ctc without the 1 flier that was my fault.... I need to do some trigger work. So all in all I am very happy with the re crown.

Its a huge improvement in how well the qb78d performs.

Bruce

Glad to here it worked out good for you, It always amazing how a crown can make a big difference if it has some dings or marks on it!

It had a bur... I did the q-tip test and once specific place would always pickup a few fibers. I shot it a bit at first to see if accuracy would improve.

I did a tune on it and when I had it apart, the barrel port was opened up and polished also to remove any burs originally it was very sharp and would damage pellets. I also polished the pellet loading port. This helped a lot with accuracy but it still was not there.

Polish the crown and voila! I know this is probably old news as its a common problem, just wanted to see if other people have had as good a success.

Bruce