This is a list of real match grade barrels commonly used in benchrest the rest are production grade barrels that are unlapped and through a borescope the finish all looks the same inside.
IMO most don't need a match grade barrel on an AR because unless they handload for precision, (not just to save money) they will never see the benefit of a match barrel.
Shilen
Lilja
Hart
Krieger
Douglas
Bartlein
Broughton
Lawton
Schneider
Border
Pac Nor
Spencer
A few others that are lapped but hardly ever hear of them being used in matches.
Lothar
Rock
On the subject of stainless, 416R(R stands for resulphurized) was designed for making gunbarrels the "R" makes the stainless have better machining qualities and reduce the brittlness that the 410 had. They say 410 should not be shot below zero but 416R is good to 40 below
from the tech forums-
CRUCIBLE 416R
Crucible 416R is a pre-hardened chromium stainless steel which is suitable for use in precision match-grade rifle barrels. It can be supplied in various hardness ranges according to your specific requirements ( HRC 24/28, 28/32, or 32/36). Crucible 416R was specifically designed by Crucible engineers in collaboration with barrel makers and rifle manufacturers to provide consistency, high quality and the following characteristics:
Good machinability for gun drilling and reaming, plus excellent polishability for uniform lapping, necessary for bore accuracy.
A homogeneous microstructure which responds to heat treat providing a uniform hardness along the length of the bar, necessary for accurate button rifling to precise groove dimensions.
An optimum combination of high tensile strength along with adequate toughness to withstand the typical chamber pressures encountered during firing.
Good corrosion resistance to inhibit rusting and which also helps to minimize fouling. Crucible 416R provides a durable finish which does not pit when properly maintained.
Precision straightened and stress relieved bars, either mill length or mult length, ready to be cut to length and gun drilled.
100% ultrasonic testing for reliable barrels.
Crucible 416R stainless steel is manufactured using very stringent controls from initial melting, through hot rolling, heat treating, cold finishing and final bar inspection. Barrels made from Crucible 416R are used at all levels of competition and in all conditions dry, damp or salty. Although all martensitic stainless steels have reduced ductility at very low temperatures, Crucible 416R can be safely used down to minus 40°F (-40°C).
Typical Chemistry
Carbon 0.12%
Chromium 12.50%
Manganese 0.40%
Phosphorus 0.03%
Sulfur 0.13%
Silicon 0.40%