Real versus actual measurments?

I am new to SimSolid.  It seems very capable and has a lot of features I have not explored.  But I have one area of concern, how does it relate to real world experience.  Below is simple pipe:

• 47” long
• wall thickness of .065”
• Material is as below, Chromoly steel.  Note that I get very similar results with AISI 4140 steel - Normalized from the default database

• Immovable at each end of the pipe (the faces)
• Load in the center  on a .25” diameter circle is 50 lbs

As you can see the calculated displacement is .044727” in the center.  Yet, if I take a piece of real chromoly pipe and load it like this its displacement is 0.165” in the lab,  a 4X difference.  Either the tool isn’t good at thin wall tubular material, or I am doing something wrong.  Given all that I have read about the product, tutorials, etc. I am inclined to think the issue is how I am using the tool.  But this is pretty simple analysis given the vast capabilities of the tool.   Thoughts?