Ever hear of a ransom rest???? Manufacturers must supply data, esp when going for a military contract. If the army wants a sub moa rifle, they get it.
Yes, I've heard of a Ransom Rest. Unfortunately, they don't make grip inserts for the XD, and I think you missed the point any way.
I'm not saying that all guns are equally accurate. A Caspian 1911 is definitely more accurate than a Beretta Tomcat, but they are completely different guns. The distinction is not so easy to make with minor variations in the same basic platform, such as the XD.
Can you or anyone else say definitively
that the XD-[insert caliber/variant] is more accurate than any other XD? Can you say that the XD-[insert caliber/variant] is more reliable than any other XD? We're not comparing apples and oranges; this is more like granny smith vs. red delicious.
You mentioned government contracts, but somehow overlooked the last line of my post: "Until someone with the proper resources does a controlled test... I'll stick with my beliefs" Testing for government contracts certainly meets my criteria, but where are the published results? Did the US Army choose a specific XD for issue to troops? Did they even test the general XD platform? To the best of my knowledge, they haven't done either, but I'd love to be proven wrong.