Bad efficiency with Kolsch--Global Kolsch issue?

So I brewed my first attempt at an AG Kolsch. According to my hydrometer reading, I am lucky if I had just under 60 percent efficiency. I did a no mash out double batch sparge. My temps were all pretty good. At the end of an hour mash it was at 151. I used the amounts of water that beersmith suggested and got pretty close on the amount on my boil volume to what bs estimated. I was at about 5.25 gallons after the hour of boiling. So, here's my question. Could the potential of Global Kolsch be less than the pilsner that I chose in BS? (BS doesn't have Global Kolsch). Would that account for the lower reading? Could the grain have been old? I really worked hard on this and expected much better results? I'm new at this. It's my third batch of beer and only my second at AG.

How's your crush? A bad crush will do terrible things to efficiency.
Since this is your second all grain batch, maybe chalk it up to inexperience and learning your system. When I first started AG my efficiency was all over the place until I got it dialed in.

I don't think the potential of Global Malt Kolsch was the issue. I brewed a Kolsch a couple months ago using this from BMW as a base malt - 7 lbs along with 2.5 lbs wheat - and put Pilsner into BeerSmith just as you did, single infusion, double batch sparge (equal volumes), no mash out. I ended up overshooting my OG by 4 points even figuring on my typical 80% efficiency. So you might think about doughballs, stirring thoroughly, or your crush.

My kolsch turned out great, btw.

Oh yeah, also make sure that BeerSmith doesn't think you're boiling for longer than you actually are.

Thanks for the insights.

The guy at the brew store dialed the crush for me. He put in on a "2" or "20". Don't know what that means, but he seemed to know his stuff. Can't say if it was right. I did stir well. I didn't see dough balls. Ah well. It may remain a mystery.

One thing though. BS doesn't have that grain listed, so the efficiency is based on a pilsner not the Kolsch. I googled "Global Kolsch" but couldn't find its potential.

Same thing happened to me last weekend! Had to use some Global since the LHB ran out of 2-row (who the F runs out of 2-row?). Missed my SG badly. I've chalked it up to some mash temp issues but this has me reconsidering....

How long was the mash? Did you check for conversion?

here was my thread
https://www.homebrewtalk.com/f36/analyze-my-brew-day-178408/