My LHBS keeps their grain mill set at .045 as I recall(I think that's what it is, I may have misplaced a zero or decimal). Is this fairly standard or should I be looking to adjust this? I just want a good crush to maximize mash efficiency.
That is a little wide. I wouldn't just go around adjusting the mill at an LHBS though. I would definitely ask. Many have a do not adjust policy. You can always run the grain through twice.
I use .045" without issue. And accomplish near 90% efficiencies depending on my sobriety.
.045 is to big for my comfort, My Barley crusher came in at .039 and I have it set to .035 now and get a 87% efficiency on average.