ER70S-6 vs. E-70S-6 MIG wire

Rod: Hi Bob, If the Forney is spooled, then no. If the Forney are electrode rods then yes. ;)
If you use straight CO2 gas, I suggest using ER70S-2 wire though.
Rod Ryker... It is reasoning and faith that bind truth.

I believe the only difference is in brand. I have never seen mig wire designated without the "R" before but Google finds a lot of it. Maybe the AWS has made a change in the term. I always found the R a bit disturbing when thinking of .023 wire as a TIG rod. Maybe that's what they use for welding thin stuff like razor blades. I've heard that the quality of MIG wire can change between different brands but I've never tried enough to know the difference. I use the house brands that the welding suppliers push on me and they seem fine.