Best gap setting for grain mill

[brew703]

I am a BIAB brewer and use a cereal killer grain mill. I've read posts about the various settings and I set the gap using a credit card. According to AIH, that gap is too small and should be .038.

The problem I have is the handle sometimes slips at the smaller gap. I have the screw tightened as much as it will go.

For those who have this mill and brew BIAB, what setting do you use? Using a larger gap would affect efficiency correct? it seems like I've read where a lot of folks use a credit card to set the gap and have no issues. I cant recall if that's using the CK or another mill.

 

[atoughram]

I set mine to 0.037" - the rollers are not centered perfectly (Runout) so I set it to 37 thou at the open position and it gets a few thou tighter as it turns.