I've got a frame that does the same thing and it's an easy open newer frame, but it only does it on one barrel, so it's not the frame. The bolts are to blame. Easy fix for me is to hold the barrel up as I sharply pull the trigger guard spur to open the action. Opens every time with no problem. The long term solution is a good Arkansas stone or some other type lap that will adjust the engagement. Be warned though, too much and you'll get the opposite problem, barrels flying open when shot. Before you get discouraged, try a different barrel and see what happens. This is a 44 mag right, see if your local gun shop will let you shoot another used barrel for half a dozen rounds or so (there's an indoor shooting range that will let you do that around here, and most of the gun shops I deal with are pretty happy to work with me, especially if there could be a sale down the line).
Good groups not on center = change point of aim and don't care where someone else shoots with it. I agree it could be a grip problem, but that will usually end up with inconsistent groups as time goes by. Everyone aims slightly different, both open sights and with optics. With open sites I've seen folks swear they are centering the blade in the notch but actually be offcenter. As long as they do the same thing consistently, so what. Optics, if you don't have your eye in exactly the same spot as another person, it changes. Much more evident with lower quality optics, but all of them do it to some extent. To prove it to yourself, lock a scope in place looking at a blank sheet of paper at 25yds or so, look through the scope and have someone put a small dot at the center of the crosshairs. Now move your eye around. If you move too far, you'll loose the picture completely, but by moving in and out and slightly up/down left/right, you'll see the crosshairs move off the dot. If your hubby and you don't have the same cheek size, face thickness, and eye to eyepiece distance, than you're gonna see an ever so slightly different point of aim (up to 2" at 100 yards depending on quality of scope). Hope it helps.
Helicopter Bill