I purchased a Model 46 from a friend earlier this year.
I've put a number of rounds downrange since, and as I was cleaning it I got the thought that the recoil spring was getting past its prime. (Nothing damaged per se, just a feeling.) I asked my friend if the spring had ever been changed, and he told me he was the second owner and hadn't changed it, so it was likely original.
I ordered one from Brownells, and installed it. The old spring measures 3 7/16", and the new one is 4 11/16".
Anyone know what the original length of a factory spring is just for comparisons sake?