I hate to see everybody knocking everybody elses products. Bushy this colt that FN this DPMS that. Chrome is the real stuff this upper is the real thing...on and on.

If we all walked in to a modern USMC Armory.

WHo makes the M4 brl blank? Who finishes it?
Who makes the real M4 upper Blank then who finishes it.
Who makes the Colapsible stock? what is considered real?

What is the metal of the brl 4140 or 4150 etc.

Are they all different?


Do the brl acutally have the manufacturers name on them? I was told they didnt....

If every thing is mil spec then I should beable to pull diff. parts together and use them in the same weapon with out a hitch.. maybe some minor tuning but each piece will last as long as the other are supposed to last according the Mil specs.. right?

I know colt as well as bushmaster makes barrels in house using 4150 chromemolly steel,FN im not sure but they make the M16A2,A3 for the militaryso I assume they use spec parts I dont know if they do barrels in house or not and Im not sure if parts the others use are made on site or not but with barrels colt and bushy do.
as far as uppers and lowers there is only a hanfull of foundrys that make forgings and then the individual company machines them to specs so I imagine more than one manufacturer gets their forgings from the same places.

1ar,

First I'll say that I'm not in the USMC.  I was on a project where we wrote an application for the USMC and I was fortunate enough to go to Camp LeJuenne and their armory.  It was freaking awesome...one of the coolest places I've ever been in.  Now, the Marines that work there were kind enough to show me the M16 and SAW.  The barrel of the M16 that I saw was stamped C MP 1/7 NATO 5.56.  That might not be the exact order but you get the point.  
As for the manufactures name on the barrel, the "C" stands for Colt and "B" stands for Bushmaster.  So, the manufacture is actually stamped on the barrel.

Hope this helps.

What difference does it make?  You ask what is real.  They are all real as long as they are well manufactured.

In the past the military has used different suppliers for the same product (i.e M1 and M14 rifles- made by: Springfield, H&R, TRW, IBM, Singer Sewing Machine Company, Winchester, plus a whole lotta other manufacturers).  

It only matters that the product meet the standard established by the government.  Also remember that the government usually gives the contract to the lowest bidder.  The lowest bidder will meet the minimum standards,  but the lowest bidder may not have the "best" product.  Currently, FN (Fabrique Nationale) and Colt supply the M16/M4 type rifles for the US military.  There is no such thing as "best"--"better" maybe but not best.  You will find some private owners in possession of AR rifles with far better parts/barrels/scopes than what the average US soldier possesses.

Only a select few USMC units have M4s (and they are M4A1s) so I doubt you'd see M4s at all [;)]


99.99% of the time it will be a Colt.  Bushmaster has had a very small run for the US Army in Desert Storm (so you'd have to visit an Army Armory to find one).


Colt finishes it - blank is produced by a foundry using Colt supplied dies (which only Colt can use).


Colt seems to make their own (their diameter is a bit smaller than the commercial ones).  You can find a variety of styles.

There is the Old style CAR stocks that were used until recently.  Now the new 'waffle pattern' stocks are being used.  The SEALs even had a special stock produced for Crane Surface Warfare center which had battery compartments (the VLTOR is a similar design concept).


Military M16/M4 barrels are 4150 steel, forged front sights, and chrome lined bore & chamber.


They are only marked with who finishes them (chamber, profile, phosphates, installs parts).


Correct in thoery - but remember there are no 'mil-spec' semi auto parts (the military uses select fire weapons).  The best the semi-guns can do is use the military specified materials and finishes on their fire-control parts.