If you have a Beretta 92 series DA/SA pistol and have not already swapped out the hammer spring with the "D" spring, as Arnold would say, "Do it! Do it now!". I have had the spring for some time now and had not got around to installing it in my 92FS Brigadier until recently because I felt the trigger on it was already really good right out of the box but glad I finally did. The Brig now has a very smooth 8 lbs. DA trigger pull and the SA now breaks crisply at just under 4 lbs. The easiest and cheapest trigger job you could ever do. My 92FS Centurion will be getting one shortly too!

The 13# Wolff spring is a good alternative also.

Or a 19lb 1911 mainspring

I actually tried a 15# Wolf spring, but was getting light primer strikes in single action.
Went back to the standard 92 spring until I can get a D spring.