Heavier recoil springs are available for all current Bersa models. Trapper Gun makes them as part of a trigger weight reduction kit. I STRONGLY advise against using the reduced power trigger return spring or hammer spring on guns you will use for self defense, as it may effect reliability. The kits are inexpensive though, so it's worth buying them just for the recoil springs.
Trapper "might" sell the recoil springs seperately. They don't have a website, but you can call them at: (586) 776-7581
You can also google for "Trapper Gun" and find online dealers selling the complete kits.
This is the only source I know of at the time for Bersa springs. Wolff refuses to make them.
Mike
We have enough youth. We need a fountain of SMART!