Fluctuating Tot Efficiency???!!!

I have been brewing all my recipes with about 70% mash eff and 75-80% tot bh eff, but the last 2 brews have made me go back to the recipe and change the tot bh eff to 63% in order to match up the OG and other figures for next time.

Is 63% way too low for a 5%abv 10 gal brew, and should I have to change the efficiency for each brew or should it be locked in...if yes, how do you predict which beers effect the tot bh eff and by how much?

If anyone wants to check out my recipes and set up I have them on the site: http://beersmithrecipes.com/listrecipes/27330/turndevil

My brews are very good but I'm just frustrated and been struggling with this for some time now!

How accurate are these recipes for what you actually experienced?

Your system only gets 4% boil off?
Are the pH and final runnings readings in the Mash tab accurate?
Are the preboil and post boil numbers in the Fermentation tab accurate?

I'm seeing some wide variations in the numbers you've recorded. I've only opened 4 recipes but two show higher preboil gravity than post, one shows just a four point rise from the boil and the fourth shows a 28 point rise.

Most often, efficiency is related to inconsistent mash pH, sparge procedures and/or malt crush.

Hi Brew Fun, thanks for taking the time to reply.

My Brew profile has changed lately because if new kit and more measurements, but I have noticed that any old recipes don't take the changes into account even when it's the same profile just adjusted. So the 2 that have the latest profile are 'How to reappear completely' and the one I have in the FV now 'HornIER Red Viper', which has stalled at 1018.

As I'm changing things like FV's, making starters and using a stir plate for first time, it's hard for me to point to one thing, however I always dotage the same and have a good mash pH so I'm not sure how to tie the lack of OG and the low attenuation (according to the predicted BS figures)!

I guess the big change in OG being effected by the tot eff change makes me nervous that I never really know where to start when I design a recipe.