Got a barrel than needs the FSB installed and then a Gordon collar fitted.  I see FSB install, but what would I select for the collar fitting?  I purchased the collar from ADCO last time they were in stock.  I know the ID needs to be opened up, but is there any fitting to be done on the front taper?  Playing around with the collar and suppressor, it appears to me the taper is larger than the ID on the back of the suppressor.

Thank you

The taper on the barrel has to be turned down.   Order the FSB install and note in the comment section you want the collar installed.  It's around $40 to get the Gordon adapter to fit.

Awesome.  Thank you.