edited cause I found the answer after looking most of the day.
This was what i found after a days worth of research:
Description of Bushmasters "DCM" Competition Rifle:
The 20" Bushmaster Extra Heavy Competition Barrel is a full 1" diameter under the handguard and is available in 1 x 8" precision rifling. They are machined from Chrome Moly Vanadium barrel steel and are hardened to Rockwell C26 to 32 - superior to stainless barrels!
This is what Bushy had to say about their barrels:
We machine our barrels from the best grade Chrome-Moly Vanadium Steel - to military specification - and we offer more than 85 different configurations Our match heavy barrels are full diameter from barrel nut to front sight base to improve heat dissipation and decreases barrel whip in rapid fire. We rifle almost all our barrels 1 turn in 9". The Gov't. originally specified a 1 in 7" twist but we have found that the 1 in 9" twist gives the best results with the widest range of ammunition, and will stabilize most bullets up to 72 grains.
And this is what I found on Armalite:
ArmaLite offers barrels made of stainless steel, 4140 chrome moly, or Mil spec chrome lined. Our chrome lined Mil Spec barrels are made of tough chrome-moly-vanadium barrel steel and are rifled at 1 turn in 9 inches ... far superior to the 1 turn in 7 inch twist government barrel.
Sabre Defence catalog begins with telling us about themselves. Towards the end, It says that their barrels are Chrome-Moly-Vanadium, but not cheap 4140, so I'm guessing 4150. If only I would have read from the beginning, instead of from the middle...