Common Culprit for Missing OG?

Hi there... not a full blown noob here, I've brewed around 60-70 AG batches within the past 3 years, and most have come out quite nicely.

However, recently I've had several batches fail to hit OG miserably.
Nothing has changed in my process, at least intentionally... I use roughly a 1.25qt/lb mash ratio, single sparge method.
Previously I narrowed the issue down to poor crush from my HBS - after inspecting the mash tun (after the mash, of course) I noticed that most grains were still fully intact and not even crushed.

Today I brewed what was to be a robust porter (14.5lb of grain), and only ended up with preboil gravity of 1.040. After adding a lb of DME and a rigorous boil only got a OG of 1.054... barely an American brown ale.

My question is... can the grain crush affect things that much? I don't know how this large, online HBS stays in business if they keep shipping out poorly ground grain... or am I the only AG brewer that has yet to buy their own barley crusher?

Any thoughts/advice would be appreciated...

and crush If you estimate the amount of your grain bill that was not crushed to expose the germ, that is the reduced amount of extractable grain in the mash. So, if you think you lost 10% you only mashed with 13 lbs of grain, if you figure it was 20%, 10.6 pounds....etc. Add to that, you probably received a poor crush of the entire grain bill which would further reduce your yield.

I would say yes, this is a crush issue completely. Great excuse to get a barley crusher.

Agreed. This appears to be a crush issue. I have a BC and it's great, a bit pricey. If you don't want to spend that much money Corona mills work as good,, some even say better. A friend of mine picked up two at a local swap meet (both brand new) for around 40 bucks total. He built a stand and hopper for it out of cheap wood and uses a drill to power it when he doesn't feel like hand grinding. I probably would have done the same thing if I was that clever.

I just bought my own crusher (MM3). Last two AG batches using grain crushed from LHBS resulted in poor efficiency (~56%). I did a test mash last weekend (only used 2-row), using identical technique, and achieved 78% when I crushed my own. Crush is everything!

Thanks for the help, everyone.

In retrospect, was there anything additional that could have been done to help compensate for the poor crush - ie I've read a little about "double sparge" methods and such - will that, or something similar help in the case of a bad crush, or can the poor crush not be made up for?

Doing more than a single batch sparge addition will inscrease your extract so little that I don't consider it to be worth the effort. Get the crush right.

oops, please delete!

I think biting the bullet for the Barley Crusher is the wise - but unfortunately somewhat pricey - next step...
I'd consider the Corona as well, though I don't like the amount of trial and error/luck involved in getting the grist right. Seems ideal for people with a tinkering temperament and a lot of patience... I want nothing less than 70%+ efficiency once I buy my mill!