Your gun should have the quick change front sight, which attaches differently than the pin-in front on this model Meprolight sight. However if you can get a red ramp quick change front sight for your R8, the Meprolight model 22770 set would work. This one has an insert that takes the place of the plastic red insert in the front sight. The rear sight blade will work with either sight set. I've got the 22770 nights on several of my work revolvers, and they work well. One 686 has had them in place for around10 years.