First thing to do is take your butt plate off and see what shim is currently in there. The mark will be on the top of the shim while it is facing you. You may be able to flip the shim to raise the DAC depending on what number is facing you.
Visit colegun.com to find the shim you want. Rich sells everything for beretta parts.
The shims are a 55/60 shim or a 45/50 shim. If you have a 45 or a 55 facing you, you can flip the shim to raise the drop. If you have a 50 facing you and want to raise to 55/60...you need to buy the 55/60 shim.
"For the High and Exalted One who lives forever, whose name is Holy says this: 'I live in a high and holy place, and with the oppressed and lowly of spirit, to revive the spirit of the lowly and revive the heart of the oppressed." - Isaiah57:15