82% Attenuation? Is that too much?

[Should drink more]

I just kegged my first hopefully improved new method Coniston Bluebird brew and it had fallen from 1039 OG to 1007 FG. This seems like a lot. It was mashed at 66, all grains no sugars, and I used White Labs Burton yeast at 21 deg.
It tasted OK at this stage but I'm surprised at the FG. Anything obvious wrong with the conditions or my logic? Thanks.

[Barley Water]

Hell no there is nothing wrong, you did just fine. I would expect an ale to attenuate the way yours did, everything sounds perfect to me. I think that too many people worry about the numbers too much, if you tasted it and it was good, don't worry about it. I know that I am just lazy but I almost never measure the final gravity of my beers. I do however taste them when I rack them from primary to secondary and also when kegging or bottling. Trust me, if the beer is under attenuated, you will know it just by the taste (at which point you can hit the beer with another load of yeast, say a neutral ale yeast like WLP01 for instance). Look at it this way, if the beer is over attenuated, what can you do about it anyway?

[mysterio]

I'm the same, I can't remember the last time I measured the final gravity of my beers. I've had US-05 yeast regularly attenuate in the 85% range. There is always a margin of error when you measure gravity anyway, depending on how you look at it, the temperature, how your hydro is calibrated.

[Stonechat]

I never measure the final gravity of my beers either. The last reading I take is on dropping, just to make sure the yeast hasn't gone dopey. I take a quality control taste at the same time and then leave the yeast in the secondary FV to bring the SG down another couple of points.
When bottling or barreling I just want to do so with the minimum risk of oxidation and don't bother with another reading. If the taste is OK, why bother?