FWIW, I'll throw in my opinion. That and $1.25 will get you a coffee at the local gas station.
(maybe)
I don't know if I would scope that 4" 629. I think maybe I would not scope it. For all the reasons the above guys have stated.
Now, that being said I own 2 629's. A pre-lock 5" with open sights and a post lock 6.5" that I have a Simmons Pro-Hunter 2-6X mounted on it. I use the open sighted gun for range, pin shoots and "plinking" as it has a very light trigger pull (2.85lbs in SA). I use the scoped one for hunting. I agree that there are times when the scope will not be your friend. If you have that buck running past you it's darn near impossible to get him in the cross hairs, and if you do, you don't know what part of him you have in there. However, in low light situations, the scope (at least my Simmons) really comes thru. It will let you see the deer when your naked eye will not, and with the variable power, it will let you see the points on the rack as well.
If your knowledgeable about your hunting grounds, and you know where the deer are going to be running (generally) when they are pushed, and when they are going to be holding up, sneaking, or stopping to look back, then you may want to think about investing in a set of the Quick Release Rings.
http://theopticzone.com/detail.aspx?ID=2581 My shootin buddy has a set of these on his 629 performance center 44 mag and they really are slick. I don't know about "true return to zero" for rifles, but for handguns, I'm certain they will bring the scope back to "minute of deer heart\lung" out to 100 yards. At least that's what I've seen on his.
So, if your in the "hey....the deer are probably going to be busting thru here like a Macy's Mothers day sale, then take off the scope...it only takes 15 seconds, if that. If it's going to be quiet, put the scope back on.
MHO
Dave