The thrust bearing id is too small to fit the cocking indicator, I know because I tried every one mcmaster carr sells that will fit the bolt body ID with the exception on 1 which I just go today. It is not a plastic bearing like that one. And the spacer, while a good alternative for shortening the BAS, for us through bolt cocking indicator guys will make it recessed in the bolt when cocked defeating the purpose of the indicator as cocked will look uncocked.