I am not trolling....this is simply an observation on my part.

Back in the days of steel firearms, the manufacturers made all or virtually all of their own parts.  You can find Mausers for example that have all Mauser parts.  A Winchester was completely made by Winchester, etc.

But as a weapon system, the M-16/AR-15 is by its nature a component firearm.  The system precludes the need to have proprietary parts.  All the the big name manufacturers contract out some or most of their parts.  I believe there are only one or two companies that are actually forging lowers.  The milling is done here and there.

Obviously, certain companies have higher standards for parts and assembly.  But when you get down to it, anyone with time and money can assemble as good an AR as available on the market.  

Is this a reasonable assumption on my part?

But when you get down to it, anyone with time and money can assemble as good an AR as available on the market.

With an AR, that statement is pretty much true. When you are buying a factory gun, the premium that you are paying for is a company that has the right tools to do the job, the experience of having assembled hundreds of AR's and a warranty that maintains a standard for the assembly of the parts.

Quoted: But as a weapon system, the M-16/AR-15 is by its nature a component firearm.  The system precludes the need to have proprietary parts.  All the the big name manufacturers contract out some or most of their parts.  I believe there are only one or two companies that are actually forging lowers.  The milling is done here and there. Obviously, certain companies have higher standards for parts and assembly.  But when you get down to it, anyone with time and money can assemble as good an AR as available on the market.   Is this a reasonable assumption on my part?

Your assumptions are reasonable.  However, companies such as Bushmaster and Colt make there own barrels and lowers were other companies contract it out.  

Quoted: Quoted: But as a weapon system, the M-16/AR-15 is by its nature a component firearm.  The system precludes the need to have proprietary parts.  All the the big name manufacturers contract out some or most of their parts.  I believe there are only one or two companies that are actually forging lowers.  The milling is done here and there. Obviously, certain companies have higher standards for parts and assembly.  But when you get down to it, anyone with time and money can assemble as good an AR as available on the market.   Is this a reasonable assumption on my part? Your assumptions are reasonable.  However, companies such as Bushmaster and Colt make there own barrels and lowers were other companies contract it out.

I dont think Bushmaster makes there own lowers and barrels

All US military smallarms can be considered parts guns.  1911a1, the Baretta m-whatever,M1,M14,M16,etc.

The design and production contracts require parts from all manufacturers and contractors to be interchangable from obe vendor to the other.

The AR 15  is just like its militaary cousin with respect to parts interchangability.  This is a huge advantage over weapons with only one parts source (like the mini-14).  

Just like M1A's, M1's and M1 carbines, if it was put together and set up by a sloppy builder, it will give trouble.  The "name" you are paying for on the AR15 just indicates the care or lack therof in assembling the rifle.

Your right the are all just  parts guns that why most people do them selfs

Quoted: The "name" you are paying for on the AR15 just indicates the care or lack therof in assembling the rifle.

Not true at all.  Colt and Bushmaster use milspec higher quality parts than the other companies.

Forged buffer tube with film lube
Upper with film lube
barrels with 4150 steel
Better made lower parts

One of the things that makes the AR nice is that it ended up being almost modular.  Its parts are outsourced to the companies that can produce them at the lowest rate.

The logic is that you get company A to make 10,000 bbls / year for you, company B to make 10,000 receivers and so on vs you only being able to make 3000 complete rifles per year.  Because the specialist companies can make so many barrels, for example they can keep costs lower.  This is because they only need to do one thing and maintain one set of equipment.  Often times they can keep quality higher as well.

This kind of prefab assembly is being done on everything from cars to nuclear submarines.  Seawolf was built this way then -assembled- at NN.