I don't think that the revolvers' weights will matter much and won't really affect felt recoil. The 6" 629 weighs 46 oz., the 4" 629 weighs 42.5 oz., and the 6" 29-2 weighs 48 oz. Although SS revolvers probably require less maintenance when carried or in the field, blued revolvers are just as tough when properly taken care of. If you will be carrying the revolver, a 4" is a little lighter and perhaps quicker to draw if needed. But if price is a consideration, I think that the blued 29-2s will always bring more than 629s, and the 4" 629 will bring more than the 6" 629. With practice, there won't be much difference in accuracy or bullet speed between the 4" and 6". Just FYI, there were fewer 6" Model 29-2s manufactured than 6-1/2" Model 29-2s, but the longer barrels are still more desirable (thanks to "Dirty Harry"). Your decision really depends on how you plan to use the revolver: only at the range, CCW, or walking out in the woods. If I were you, I'd strongly consider the 4" 629 if the price was right. It would be a suitable revolver for all three uses. However as a novice collector, I'd pick the 6" Model 29-2 if condition was nice.
