Foreman said my feeds and speeds were 'polite' and I've been thinking about it for 6 weeks
He walked past my mill at the shop in Tulsa and said I was leaving cycle time on the table by running my 1/2 inch end mill at 40 percent of what the insert could take, so I bumped it up on scrap aluminum and the finish actually got better. Curious what chipload you guys run on 6061 with a 3 flute, because I'm still nervous about pushing it on the good parts.
My old boss used to call stuff like that "grandma speeds" and then one day he crashed a face mill into a vise running hot feeds, so there's a middle ground somewhere. I ran a 3 flute on 6061 for years and settled around .008 to .012 chipload depending on the radial depth, with the spindle screaming at 8000 rpm. The finish got worse when I went too light because the tool just rubbed instead of cutting. Maybe bump it in small steps on the good parts and watch your spindle load meter.