If you cannot articulate and demonstrate dimensional conformity of each of your home-built firearm's parts you're blowing smoke.
Back in the day Colt's claim to fame was/is metrics. They did not make everything in house but had machines checking incoming components and machines checking those machines that checked the components. That was for mil contract. I cannot remember if our armorer instructor actually said LE guns came from mil line in those days.
That works fine if your buyers do not request changes in design and all but guarantee orders. Otherwise your product, reliable as it may be, becomes developmentally stagnant. Colt choked hard after losing exclusive contracts with a narrow customer base. And they didn't choke just once. They offered some interesting things, including cheaper priced guns with model numbers similar to LE offerings.
I don't know how Colt stands today with regard to metrics/quality. But cheaper usually means something was streamlined along the way. Could be they just have to cut margins to play in the market of the last several years. I personally won't buy any.
I find others such as BCM (in spite of keymod) offer the quality and everything I need as a regular Joe. I do depend on them to be the SMEs and I am willing to pay the price.