Awesome, so basically the major components are colt manufactured?
Yes.
Most gun makers have core product models that they actually make. Some like Colt buy guns or parts from other makers and assemble them. An example was the 1960's Colt .25 Automatic that Colt had made in Spain, and the Sauer-Colt rifles.
Many AR rifle makers don't actually manufacture anything, they buy semi finished or fully finished components and just assemble them. There are companies that make semi or fully finished AR uppers and lowers and sell them to other companies.
These makers will put your company name on them so you too can be an AR rifle "maker".
Most gun makers don't make each and every part because it costs to much to buy the machinery, hire and train the workers, and devote factory floor space to make a small pin or spring that can be bought cheaper from a company that specializes in that.
In Colt's the M4 is a core product for which they buy raw forgings of the upper and lower and barrel blanks which they machine to finished parts and assemble with purchased small parts to build a finished rifle.
For the upper and lower what Colt receives is a lump of aluminum in the vague shape of a part. They do all the machining and finishing.
As an added bonus with a Colt M4, since it wouldn't be economical to run two totally separate production lines, one for a US government M4 and one or a commercial M4, Colt produces both on much the same machinery.
The only difference is that Colt machines one lower to accept full-auto trigger groups and other lowers that will only take semi-auto triggers.
They machine one barrel blank in 13 inch length for the government and a commercial barrel in 16 inch length.
All other parts are the same for both rifles, which meet the US Government contract standards.
No other AR rifle maker does this for commercial rifles. Other commercial makers don't have to meet any standards and can use parts from China if they want.
So, when you buy a Colt M4 you're getting the same rifle the police and military get except your's is not a full-auto rifle.
And if your local police don't issue full-auto rifles, they get the same rifle you do.
This is what's meant by Colt commercial rifles being "Mil-spec".
They aren't true military specification because they aren't full-auto, but they're made from the same parts that on military rifles have to meet the US government contract specifications.
This is based on the information I assume is still valid the last I heard.