This has been my experience, either a pistol fits you or it does not. Changing the grip really does nothing to the fit, if it feels right the moment you pick it up, then it is right. The 629 was not a fit. Since you reload, pick the weight of bullet you want to use and down load it to where it is comfortable, now start to increase the power, but stay with that bullet weight. Different weight bullets recoil differently, so working up with a light bullet and then switching to a heavier bullet and backing off the powder charge to duplicate the recoil of the lighter bullet does not work, it is not the same.
Personally, a stiff loaded 41mag is more comfortable to me than a normal 44mag load in the same gun, have you considered the 41mag?