So the past 2 beers I have have made my OG gravity has been off by as much as .20 of what it's supposed to be and I am wondering why. I have followed the recipes exactly and have double checked the anticipated measurements with brewtarget software.
Cool. Thanks for all the info, lesson learned, stir the hell out of it!
The simple way to get a good gravity reading is to take it after you've aerated your wort, assuming you're oxygenating your brew by rocking or stirring your fermentor.
Personally, I would calculate the SG and go with that. If it's an extract batch, the OG will be pretty close to whatever you calculate, even using steeping grains.