Without doing a lot of research into Windham, I'll offer this:
First, as I read it, unless you pay extra, on most WW rifles you DO NOT get a hard chrome lined bore and chamber.
On Colt you do.
Many makers are using the "Chrome Moly" steel term to allow unwary buyers to think they're getting a chrome LINED bore and chamber.
Chrome Moly is nothing more than a barrel steel that's been used since the 1930's, it does not mean chrome lined.
There's a $300 difference between the WW and the Colt.
Contrary to popular belief, Colt does NOT charge $300 dollars more just because it has a Pony and the name Colt on it.
What you get for the extra money is a first line firearm made of US military specification parts, carefully inspected, and with top of the line workmanship, not just on the parts, but also on the assembly.
Colt makes most of their own parts, and since the commercial rifles are the same rifles Colt sells to the police, they're built with the same military specification parts.
According to Brent Turchi, Colt's Custom Shop manager, Colt Defense, makers of military and police AR and M16 firearms, simply "pass the rifles over the wall to Colt Firearms, sellers of commercial firearms.
In other words, the Colt M4 you buy at Wal-mart is exactly the same rifle Colt Defense sells to the police.
WW gets it's parts from who knows who, and made to whatever specification or lack of specification they want.