Pretty sure Ruger won’t work on the Speed Six because that model has been discontinued for quite some time. I called them awhile back concerning a Police Service Six and was told that.If it were mine, it would get a trip back to the Mothership.
Sent in my Single-Six for a accuracy/timing issue. They did do the transfer bar change, returning the old parts.
It came back very accurate, and if anything, the trigger was Better!
Zero cost to me.
Joe