Is Brew Target telling me lies?

Hey All,

I have been looking at Pliney the Elder clones and they all seem to have really high gravities. Which doesn't seem to fit with the recipe here: http://beerdujour.com/Recipes/1Pliny the Elder clone PDF.pdf

I have put together a recipe in Brew Target which seems to be correct, but it is radically different from anything I've seen. Is brew target lying to me or is everyone making their clones too big?

Does this grain bill look correct?

Pliney - American IPA
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Batch Size: 5.000 gal
Boil Size: 3.500 gal
Boil Time: 60.00 min
Efficiency: 70%
OG: 1.070
FG: 1.017
ABV: 6.8%
Bitterness: 309.5 IBUs (Tinseth)
Color: 9 SRM (Mosher)

Fermentables
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4.500 lb - Pale Liquid Extract Extract
6.000 oz - Corn Sugar (Dextrose)
2.000 lb - Pale Malt (2 Row) US
5.000 oz - Caramel/Crystal Malt - 40L
5.000 oz - Cara-Pils/Dextrine

Most of the recipes are for 6 gallons, with the assumption that 1 gallon will be sucked up by the hops. This will be an even bigger problem for you because you are doing a partial boil (so the hops will suck up higher gravity wort). Even at 70% efficiency and no loss to the hops I only get 1.054 for your OG (it would take about 9 lbs of LME total to get you there). Maybe you have the software set to a 3.5 gallon batch?

You'll also have a problem getting the beer bitter enough since you'll saturate your 3.5 gallon boil with 100 IBUs and then dilute to 5 gallons and only have 70 (and that is only if you finish the boil with 3.5 gallons of wort in your fermenter). You should consider doing two boils (brew half the batch, then the other half later or the next day), so you can get better hop utilization, lose less gravity, and keep the color lighter.