I opened the chokes in a pair of Lefever'Optimus'12b bbls. Orig. choke Dim were both L/R 041" Opened the L to .005" rt to .009". I kept a magnet under paper when cleaning off the 'Swarf'.The total weight I collected with the cutting oil, was 3/4 of oz.This was not a 'Real precision measurement'I used my 'Postal scale'I have a photo of the 3/4oz in a plastic container in the W/shop. cc/dt