I've recently hit 1200-1300(ish) rnds with my Sig Sauer Mosquito I bought off another member here... Almost a year, with said amount of rounds. ZERO failures with mixed ammo. Even shooting subsonics with a suppressor.
If you can find one of those, they can had for $200 dollar range. Some people don't like em. I Personally can't see why. Mine has been great. I don't safe queen it either. It stays in center console of my vehicle, getting banged up daily, and shot on a regular basis.