My little Glock 26.
I bought it used, so don't know what its total lifetime count is ... but I've put an awful dang lot of rounds through it. Lessee, figuring August-to-August because that's the month I bought it:
First two years was roughly 200 rds per month (sometimes more) so that'd be 2 x 12 x 200 = 4800
Last year was roughly 400 rds per month. 12 x 400 = 4800
This year, I've averaged around 500 or 600 a month out of it. (More since summer started.) Say 550/month. 11 x 550 = 6050
Total round count, give or take a bunch: 15,650
I've replaced various internal parts along the way, and the gun has only failed me once (a broken take down spring, which I'd never replaced and which broke when I was at ~ 10,000 rounds).
pax