Dude, no way! Hard to believe. Can you give me some exact numbers on what you did, what malt, how many pounds, etc.?
Sure. Here are the specs:
10.5# Great Western 2 Row
1# Great Western White Wheat
1# Best Maltz Munich
.5# Best Maltz Dark Munich
Total Grain= 13# (This number is very exact, I measure out my grain with my wife's baking scales)
5.3 gallons or 21.2 qts of water added to the mash total (this of course could be off by a bit, brewing on this scale is such a ***** when it comes to percentage of error due to small batch sizes)
Mash Thickness= 1.63 qts/lb
According to Kai's chart this would result in a reading of 18.4ºP
My reading=17.7ºP (1.073 actually, but taken with a lab grade hydrometer at 67ºF, so very accurate, and converted)
17.7/18.4=.9619 or 96.19%
I use a 10 gallon Blichmann pot as a MT with their button louver false bottom and recirculate it through my rims tube and back into the pot via an autosparge.
There are the analytical, now for the antidotal. I used to crush my grain down to .035. I'd experimented a lot and even gone as tight as .025. I'm 49 batches in and I never really saw consistent gains (sometimes even lower mash efficiencies) from such a tight crush and I was having recirc issues and lower than desired lautering performance. So I went back to my .035" without thinking about it. I then listened to the seminar from from NHC last year on "How good is your grist" (here is a link if you are an AHA member:
http://www.homebrewersassociation.org/how-to-brew/resources/conference-seminars/ it's under 2014). At this point I still kept on going at .035. Then I came across this article
https://www.brewmagic.com/blog/follow-me-to-higher-efficiencies/. I decided to loosen up the mill to .042 (a little tighter than he suggest and the NHC seminar, but I'm a Hitchhikers Guide fan and it felt right). Seems to work great. My recirc and run off were better than ever. I attribute it to more even flow through the grain bed. Good luck man.