To fully support a heavy revolver, and to best conceal the large profile, I recommend a pancake style holster. The weight is distributed over the strong side hip. The revolver is carried high and pulled into the body by the tension of the belt. The smooth outer shell of the pancake style holster allows the outer garment to glide over the holstered weapon, minimizing "printing" of the weapon through the outer garment.
As noted by flop-shank above, a sturdy belt helps a lot. Belts made of lightweight leathers, and narrow belts, frequently tightening to an uncomfortable degree to support the weight and keep the holster positioned properly.
I make holsters for your 629, as well as heavy-duty gunbelts. Click on my username to display my e-mail address if you are interested.