Hello.....many years ago, I used to shoot a 38 super 1911 with a long slide....set up by a local gunsmith....Eddie Jimenea.  I was shooting it double tap and it was a lot of fun seeing all the "two bullets holes touching".  I was using a load of Winchester 231 and a 150 grain lead round nose.  I don't remember the exact load....but I am sure you can find it in a lot of places.
George