Have been using the Model B hi-speed for several months with stainless steel.
Like it much more than the vibrator type. Tip: After tumbling, to seperate the stainless steel pins from brass, use a 5 gal. nylon paint filter fabric that fits over a 5 gal. bucket and the miners seperator pan and pour all brass,s.s. pins and water into bucket. Will have to stir the brass and ss pins around in miners pan to get the pins to fall into the paint filter and bucket. To rinse off soap off the brass, I have a shorter bucket (cut down from a 5 gal.bucket) I fill with clean water and add the brass and then dry brass on newspaper. The ss pins in the nylon filter sock can be rinsed off and added back into tumbler. All my stuff is done outside and in shop with less than ten gals. Rinse water poured onto the grass. I suppose there is ground contamination, but figure the contents came from the ground to begin with. Have noticed that the brass wasn't as brilliant brite shiney after a half a dozen times tumbling and think the ss pins have smooth out some.