RE: How did they do it?
Like all have stated, lots of practice. I cast my ownmilli-balls so my expense is just powder and primers so I shoot lots (don't know why but love the smell of pyrodex). When comparing shooting my ML to my rifles, there is that split second between primer and charge going off. It was more when I was using my sidelock compared to my inline but it is still there. Really concentrate holding position after the trigger is squeezed.