I'm brewing a barleywine tomorrow night and was toying with the idea of doing a no-sparge and then a second mash for a lower gravity beer. I use a 48 qt. cooler and according to my program, if I use 21 lbs. of grain and a 1.77 water/grain ration, I should get around 6.8 gallons. It also says my total mash volume including grains is 10.9 gallons, which would be almost capacity for my mashtun.
So my question is, do these numbers seem reasonable? I have tried to find some reference to the volume of grain when saturated and come up with nothing. Also, how much should I adjust my expected efficiency when using this method? I calculated my recipe using 60% to be on the safe side.
If anyone has had any experience with this I would appreciate some pointers.