Strike Water Temperature

I am having some issues getting BeerSmith to calculate strike water temps for my system. I'll start by giving my setup and hopefully someone has already been in this situation.

I have a single tier, 3 vessel system made from 15.5 gal kegs. All 3 vessels are direct fired. I begin my brew day by adding water to my mash tun at 1.2 qt/lb. and heating that water to 5˚ above my desired strike temp. Once the water has reached that temp i allow it to recirculate for a few minutes just to make sure it's stable. I drop the temp controller setting down 5˚ to my desired mash temp. I continue to recirculate and then dump all of the grain in to the tun at once then stir. The temp drops 5˚ and all is well.

The problem i have with BeerSmith is that it is always indicating my strike water temp is 10˚-11˚ above my mash temp when in reality it should be around 5˚.

One reason I really want this to be dialed in is when i approach capacity making higher gravity beers. I often have to drop my water/grain ratio to fit it all in. When I do this the grain addition obviously drops the mash temp more and I'd like BeerSmith to tell me how much. It's also just frustrating me seeing this number be incorrect, i now I'm missing something.

The default of 10 to 11F works for me, but maybe my system and process fits the assumptions that Brad used when he set the MT Specific Heat for stainless at 0.12.

Maybe a recirc system compensates for s/s losing some energy, and so performs more like plastic or whatever.  And thus acts like it has a higher specific heat. 

You can adjust that number in your equipment profile and tinker until you get the 5F delta you seek. 

I've tried the adjustments for specific heat and for tun temp. Neither give me more than a couple degrees at most.

I turn the mash temp sensor down to the desired mash temp before mashing in so the tun is usually not fired until a few minutes after I'm done mixing the mash. The flame is not effecting the amount of temp drop when mashing in.

Export and Post your equipment profile file so people can see it.  That usually helps with suggestions.

I also use 1.2 qt/lb and the 10-12F works for me, so I now think it's a volume issue.  Since you're hitting strike with only 5F hotter water, that makes me guess you're using more water than BSmith is estimating. 

How confident are you that you're within one quart on all your volumes?