learn to use either hand, and both
Hi,
my initial handgun training dates back to the eighties, when I was in a military HR team.
I am now more than double the age I was then, but the reasons for what I learned still make sense.
IMO one should learn and practice shooting with either hand (and off course with both hands). not only that you may not be able (for a myriad of possible reasons) to use both hands, but being able to whoot with either one of your hands allows you to make best use of cover. by shooting single handed from the side of a cover, you will expose much less of your VITAL parts comparing to using both hands.
I therefore practice regularly with my pistols and revolvers ( including, coincidentally a 1911 and a S&W 586) all 3 options (right hand, left hand, both hands)
In competitions (IDPA, Pin-shooting and metal silouhette) I always use two hands except in drills that require single handed shooting.
To pre-empt any "mall ninja" comments, Where I live the possibility of having to defend yourself is VERY real; and even if it only happens once in your life, you may want to give yourself the best chance to survive it. My answer addresses fun shooting as well as SD practice.
Cheers,
Danny