Varying OG using Beersmith 2

I have now done 5 recipes with Beersmith 2. I have not had any major mess ups and have had OG's from .005 over target to .004 low.

Anyone have any suggestions on what to look at to refine this further?

Rye IPA .005 high of target
Wheat Beer .003 low
California Common .004 low
Porter .003 high
Ultra Pale Ale .003 low

I crush my own grain and think I get a good crush and have not changed any setting.

I created an equipment profile and have not changed it. I also have left the Tot Efficiency at 72%

The first two of these have both been good, the others are not finished.
I used Beer Calculus for several batches prior and had the same type of variance. I just didn't worry and all the beer has been good.

Is this range normal or should I work to refine it?

That's a normal range. My suggestion, if you want to dial in your process, is to slow down the speed of your lauter, or at least ensure that it is constant. Just throwing the knob to "open" every time isn't good enough; ensure that you're getting the same flow-rate with every beer and you'll get greater consistency.