Arrogant Bastard clone/steep vs. partial mash question

This is my second batch, using an Arrogant Bastard clone recipe from my LHBS.

Ingredients:
6.6 lbs Light Muntons Malt, 3 lbs light DME
Specialty Grains, crushed: 1.5 lbs dark Crystal
Hops: 2 oz Chinook, 1 oz Warrior
Wyeast 1098

Approx. SG: 1.072 - FG: 1.014

The instructions said to place the steeping grains in the muslin bag, place in 2 gal cold water, bring to 160 deg and hold for 10 min. Instead, I brought 2 quarts water to 160, steeped (mashed?) the grain at 160 for 30 min, then brought the wort to a boil, rinsed the grains in about 2 more gallons and continued as per the instructions with a 4 gal boil reducing to 3.5 gal after 60 min. I cooled, topped off to 5 gal in the primary, and pitched.

I ended up with an SG of 1.083. It has been 19 days in the primary at around 62 deg, and I still get a little activity in the airlock (once every 5 min), and the sample I just took measures 1.022, and is a little sweeter than Arrogant Bastard. I plan to leave it until the gravity stops changing. Did I get a higher SG by steeping the grains for 30 min instead of 10? Also, is fermentation taking a while because I only used 1 pack? I smacked it 4 hours before I pitched, and the pouch had puffed out.

I would definitely give it more time to ferment. With that high of an OG and that low of a ferm temp (62F) its gonna take a while. I would say give it a good month to a month and a half to ferment out totally.

With that high of an OG, you would've really benefited from making a starter to get your yeast cell count up. It should finish, but might have a little trouble getting down since you underpitched by a bit. Give it time. If it's really balky, give it a gentle swirl and see if you can warm it up a little to about 65 to see if that helps. It may also just be finishing high due to unfermentables in your extract. Either way, time is what you want.

So, according to Palmer
http://www.howtobrew.com/section2/chapter12-4-1.html
Dark Crystal will yield 16 ppg if steeped, vs 28 ppg if mashed, am I reading that chart correctly? So it is possible that my OG was affected by mashing/steeping for 30 min instead of 10, and then sparging instead of discarding?

I'm guessing you ended up with slightly less volume than the recipe calls for. That's the most likely explanation. It's also possible that you had a little more extract.

Thanks for all the replies. I'm not in any hurry, and I'm happy to let it sit a few weeks more. I might use the time to dry hop it. The hydro sample tasted great, so I'm looking forward to the finished product. I don't think I was off on the final volume, it was right at the 5 gallon mark on the bucket. Also, the malt extracts were in cans and a sealed bag, so I don't think they could be off. Just curious about the process, and steeping vs. mashing, as I'll need to learn more to get into AG.

Oh, I realized I could have been low on volume because the Chinook was whole leaf hops, but I did pour the wort into the fermenter through a strainer, so I didn't have hops taking up some volume in the primary.