Mash Efficiency

Greetings: I am relatively new to all-grain brewing so forgive this question if it seems out of line.

I have brewed about 5 batches of various styles and all I can seem to achieve is 59-60% efficiency from my system.  Is that normal?  I am using a Igloo cooler with false bottom.  I gravity feed to a boil kettle, then pump through a plate cooler into my carboy.  I have tried everything I can think of.  I typically do a single infusion mash and a batch sparge.  Please don't get me wrong, my brews are outstanding.  It just seems like I should be able to extract more from my grain - like 70-75% maybe.  I grind my grain at the local brew store where I buy my grain.  Any ideas??

with out knowing the brew shop's grain mill gap, it will be hard to know if that is your problem but if you post a pic of your milled grain I'm sure some one will help.
I find that most shops mills are not tight enough, but all grains are different so they just set it and forget it.
mash ph can also lead to low conversion. then there it the equipment you use. I suggest you batch sprage until your running's are < 1.020 and >1.012 if your not doing that already. don't sparge if the gravity is below 1.012.
Now I use ro water to sprage with if you use really hard water it can raise the ph of the wert to high, then cause off flavors.
  All an all you should tell us more about your process. water profile, mash temps, mash thickness, mash PH, mash times.  This would make it a lot easier to figure out what is going on. thanks.

And try verifying all your measurements.  Only five batches in, it's easy to have some of the volumes wrongs, which affects everything.

You could ask your supplier to double crush your next order to see if it makes a difference.

Greetings All,

I believe All Grain nailed it.  I believe the mill at my local shop is not set properly.  I have done some research as well and many people are pointing to the same factor - the "double crush" is an interesting idea.  Also, I do maintain a good pH while mashing.  However, I have not considered the pH while sparging.  I like the RO sparge water concept.  So, you have all given me some very notable points to consider on my next batch.  Thank you all very much.

Bottoms Up!!

Keller, there is a plethora of excellent advice in this thread on efficiency problems and how to find out where you are losing it  from very smart brewers.  My experience with a similar problem was I wish to heck I had started with the crush instead of finishing with it.
http://www.beersmith.com/forum/index.php/topic,10779.msg43771/topicseen.html#msg43771

My first big improvement with efficiency was mashing out. Added five percent or so. My second was tightening up my Corona mill a bit. That added quite a bit.  My third will be buying a roller mill. Wish I'd purchased a roller mill first.