I recommend this adapter:-
http://www.iceinspace.com.au/forum/s...ad.php?t=50200
http://www.astromart.com/articles/ar...article_id=651
But if you stay with the brass compression ring and are annoyed with a barrel undercut being caught, there is a solution:-
http://www.iceinspace.com.au/forum/s...ad.php?t=58498
I have only applied it to my 2" barrel eyepieces since I always use my 1.25" eyepieces in the Antares adapter which has smooth sides.
EDIT - I should mention that the Antares adapter does lift the eyepiece somewhat further out of the focuser draw tube than simpler adapters. Harder to try and get eyepieces parfocal - 2" compared with 1.25" in adapters