BIAB is killing me!

Efficiency wise that is. I had a problem with too fine a grind and backed off a full turn on my mill and got 74% efficiency which was what I got before BIAB, so I tightened it uo a little over half a turn as I was using up 6#'s of Rye extract I had left over. I wanted a version of Rye Knot brown ale and with less than five pounds of grist I didn't think much about it. Mashed for an hour at 151F and added another gallon of water and raised the temp to 170F and drained the bag in another pot after a long stir. Went merrily on my way and added the extract and completed the brew. I go to check the OG and I see 1.076 where my target was 1.058! Really? I added as much water as I could and still had 1.074 when I pitched the S-05. I don't even know what kind of beer to call it? 8% alcohol in a brown ale........naw, I don't know what it is. I gotta get this fixed, I just never thought four+ pounds of grain could do this. Now I'll adjust grain bills and get low efficiency.....I see it coming.