Hello Dr. D, saying that you will be welding steel studs and channels that are roughly 16 GA. and used for a structural purpose tips me off to believe that these might also be galvanized. My own experiences with this type of scenario would suggest that you go with an innershield wire to avoid problems with porosity in your welds, this may also save you a lot of prep. time in avoiding a bunch of grinding, as far as the type or brand, I would suggest any of the name brands (Lincoln, ESAB, Corex, McKay, Tri-Mark, etc.), I believe that the AWS classification is E71T-11. If you really are stuck on running a dualshield wire for this job, a really good one that runs exceptionally well on straight CO2 is Lincoln Outershield 71. Good luck and regards, aevald