LOL, try a S&W 500.I shot one a few times and it was literally a blast to shoot.
As a matter of fact, I was just shooting my M&P 9mm today at the range and in the middle of a mag I heard a "BOOM!" from down the lanes. Everyone around me stopped shooting and said "what the heck was that?" It didn't even effect me knowing full well that it was the S&W 500 rental and once I was done with my mag, I looked back and everyone is looking at the guy shooting it. I tell them what it is and get back to shooting, hearing BOOM after BOOM and realized I was the only other one shooting. Obviously nobody else could concentrate.
As already suggested, a .22lr pistols and some snap caps for your other guns does wonders. I usually have a target taped to a wall and practice dry firing focusing only on the front sight and target. If you drown out everything else around you and focuse on what your doing. nothing will effect you as much, if at all. The .22lr handgun is your best bet though since you get some feedback unlike dry firing. Trigger pull has a lot to do with it as well. If your pulling to slowly or anticipating where the trigger breaks, it may make you flinch. Get enough practice in, make the gun second nature and shooting will be as easy as breathing.
