Partial Mash Efficiency Questions

[GHC007]

So, I just finished my brew day, made a Pliny the Elder clone using DeathBrewers Easy PM (only my 3nd PM). Ive been searching on the site for the last hour or so and keep finding contradicting responses. I mashed for 60 minutes at 151, sparged for 10 minutes at 160 and measured my pre-boil wort (3.75 gallons) at 1.054 (adjusted for temp) which I was pumped about. After the boil, I cooled, then topped off to get to 5.25 gallons and mixed as well as I could and the hydrometer read 1.064. Ive read all the posts about not mixing well enough and im hopefully chalking the low reading up to that but Id like some reassurance. By my calculations 1.054 mashed wort + the 1.026 contributed from the 3# of DME added in the boil would've pegged the OG @ 1.080 and an efficiency in the 80%s, am I way off base here. Below is the recipe, thanks for any help.

Type: Partial Mash
Date: 7/30/2012
Batch Size: 5.25 gal
Brewer: Andy
Boil Size: 3.75 gal Asst Brewer:
Boil Time: 90 min Equipment: Brew Pot (5 Gallon)
Taste Rating(out of 50): 35.0 Brewhouse Efficiency: 85.00??
Taste Notes:

Ingredients

Amount Item Type % or IBU
3.00 lb Extra Light Dry Extract (3.0 SRM) Dry Extract 25.00 %
7.00 lb Pale Malt (2 Row) US (2.0 SRM) Grain 58.33 %
0.50 lb Cara-Pils/Dextrine (2.0 SRM) Grain 4.17 %
0.50 lb Caramel/Crystal Malt - 40L (40.0 SRM) Grain 4.17 %
1.00 oz Columbus (Tomahawk) [14.00 %] (Dry Hop 12 days) Hops -
3.50 oz Columbus (Tomahawk) [14.00 %] (90 min) Hops 104.8 IBU
0.25 oz Centennial [10.00 %] (Dry Hop 5 days) Hops -
0.25 oz Columbus (Tomahawk) [14.00 %] (Dry Hop 5 days) Hops -
1.00 oz Simcoe [13.00 %] (Dry Hop 12 days) Hops -
1.00 oz Centennial [10.00 %] (Dry Hop 12 days) Hops -
0.25 oz Simcoe [13.00 %] (Dry Hop 5 days) Hops -
0.75 oz Columbus (Tomahawk) [14.00 %] (45 min) Hops 19.3 IBU
1.00 oz Simcoe [13.00 %] (30 min) Hops 20.0 IBU
2.50 oz Simcoe [13.00 %] (0 min) Hops -
1.00 oz Centennial [10.00 %] (0 min) Hops -
0.25 tsp Irish Moss (Boil 15.0 min) Misc
1.00 lb Corn Sugar (Dextrose) (0.0 SRM) Sugar 8.33 %
1.50 gal Distilled Water Water
1 Pkgs Safale US-05 (Safale) Yeast-Ale

 

[Calder]

Let see if I can find some rationale of what you have.

1.054 in 3.75 gallons = 202 points. You added 3 lbs of DME (or 138 points) = 340 gravity points.

In 5.25 gallons = 340/5.25 = 1.065. That's pretty close to what you measured.

 

[GHC007]

Thanks for the response! If thats the case BeerSmith puts me under 60% efficiency, any thoughts on why that would be so low? Or is that normal with my method? The crush looked good and came straight from the LHBS.