Ok 1st time brewing from a recipe rather than a kit. I decided to do an Epic Pale Ale clone. After a mix up at MoreBeer I had to change my specialty grain bill. The target OG was 1.052 but for some reason I came in at 1.042. Where did I go wrong?

Fermentables
Ingredient Amount % MCU When
US Crystal 15L Malt 0.50 lb 6.2 % 1.6 In Mash/Steeped
UK Caramalt 0.50 lb 6.2 % 1.3 In Mash/Steeped
US Carapils Malt 0.50 lb 6.2 % 0.1 In Mash/Steeped
Extract - Light Liquid Malt Extract 6.50 lb 81.2 % 4.0 Start Of Boil

Boil Notes
Steep grains and removed at 170 degrees. Turned off flame and added LME. 90 minute boil. Only could chill till 71 degrees. Racked to carboy at 71.

Was it a partial boil? If so, you likely didn't get full mix between wort and top off water. Otherwise you likely had either a faulty reading hydrometer or a larger volume than the recipe called for.

Full boil. 6gal at start 5.25 at end. I'm using Beer Alchemy for my recipes. The hydrometer might be the case. I'll borrow another to check.

Is the recipe expecting 5.25 at the end? You can just calibrate in water with your hydro... if you're reading 1.000, you should be good. Was the OG you are expecting one that came with the kit or o en you calculated?

The one thing that stands out to me is the 6.5 lbs of LME. Most of the LME I've seen at More Beer comes in a 1 lb increments (4, 5, 6, 7, 8 or 9lbs). Is it possible that you actually used 6 lbs of LME instead of 6.5?