Man, talk about knocking on wood. I have run over 200,000 rounds of +p ammo threw three different M-9's and yet to have a lock crack. MY guess is that I kept the pistols sprung correctly, and may have been my saving factor.
As noted, if the pistol was bought new, then Beretta might fix if for free. If not, just call them up and order a new lock. Also, now would be a good time to get Wolf on the phone and order up a few replacement recoil springs at the same time. The recoil springs seem to start giving up the ghost around the 4000 mark (father than normal ejection distance), so if you are not watching the ejections, then use the 4000 count rule as a replacement guide.
Note, for +p ammo, I use a 16 lb recoil spring, and for standard hard ball ammo, a 15 lb spring. The factory 13 spring only give me the correct ejection distance when using light reloads (read crap that you have to buy when you show up at a indoor range and all you have is jacket ammo (and they only allow cast bullet ammo
).