ronbow - nope, they won't cure your lousy shooting so save your money. If you can hit better, more reliably and more consistently with a revolver then why the semi-auto?? None the less it is your choice and far be it from me to discourage the additional practice necessary to improve your shooting with an autoloader.
There may be many factors to your performance with different handguns. A lazer sight on the Beretta will just add weight and bulk and may even serve to worsen your shooting performance with that handgun.
I do not know how you practice with your handguns but I would first suggest bench resting the handgun to determine its capability with your chosen brand of ammo. The next step would be to work on your grip, sight picture, breath control and trigger pull. The same principals that apply to accurate revolver shooting also apply to pistol shooting, regarding grip, sight picture, breath control and trigger pull. JMTCW but HTH. Mikey.