What are you hitting now for efficiency and do you have your own mill? There is a method some of the guys in my local brew club are experimenting with and having some great results. They are misting the grain before crush with a few ounces of water in a spray bottle. They mist it down and let it sit about 3 to 5 minutes to soak in slightly. Then they crush. It cuts down on the dust and the husks do not shred as bad. They are able to dial the rollers of the mill for a smaller or finer crush which helps them hit efficiencies in the mid to high 80's. I have not tried it yet but I seem to not have any efficiency problems to worry about. I just run a normal crush on my mill and normally hit 76% to 78% on my system. I can say if your mashtun is not well setup you can get a stuck mash fairly easily with a crush that is fine. Buddy of mine just had that happen when he crushed is grain nearly to a flour. Took him two hours of stirring and straining to get the wort out of the mashtun and even after that it was very cloudy in the boil kettle. He is going to have a hell of a time clearing that beer up after fermentation.