My apologies if this has been covered before, but the front sight insert on my 29-2 is wobbling around in it's dovetail. Is there a common fix for this?

Several of my older revolvers with the red ramp insert (not just Model 29's) had the same problem. The plastic insert tends to shrink over time, causing the sight to wobble. Don't wiggle it too much, or you could break the two small portions of the red plastic insert that fill in the holes drilled in the base of the front sight that hold the red insert in, or it might fall out.
What I have done in the past, is use some super glue (only need a very small amount) on a needle/pin head and carefully put some glue in areas around/under the red insert carefully without getting any on the gun itself, and let it dry. This should hold the sight insert. Hope that helps.

Thanks, was kind of thinking along those lines.