You won't likely to too wrong with either.
The .44 mag is a bit simpler.
(1) The last 2 blued .45 colt Blackhawks had front sights that were too short to get 'em sighted in with 250 grain or heavier bullets. Cowboy loads were only a couple inches too high, everything else was just ridiculous. No issues of that sort with the SS .45s, they had much taller front sights.
(That's not to say .44s are problem free, I've had 2 that I couldn't sight in with 300 grain bullets, but I've never had one I couldn't sight in with normal 240-250 grain bullets and max loads.)
(2) Bullet availability ... in this small town, .45 colt JHPs are not to be found. Special order only. There are 3-4 different .44 mag bullets available over the counter.
That doesn't matter if you shoot lead and cast your own though.
I've carried both .44 mag and .45 colt over quite a few years and I'm perfectly happy with either caliber once the individual gun's kinks are sorted out so the bullets hit where the sights are.
Tom
