I have a glock model 22 that I purchased as a used police pistol. I have put 2,500 rounds threw it. I had 3 ftf due to worn magazine springs. My groupings started getting worse so I sent it to Glock. They replaced the firing pin, barrel, trigger assembly, front sight and recoil spring for free. I don't know how many rounds were shot threw it before I got it but I does look used. I have not had one issue since the replacement parts and accuracy has improved. I have 500 rounds since the replacements.
A hit with a .22 is better than a miss with a .44