Had Mec-Gar mags for Ruger P89 and Beretta 92, completely flawless functionality.
Had 2 Promag 1911 magazines (10 rounders) and returned them after my first trip to the range.
18 failure to feeds in 50 rounds fired, extremely disappointing.
Moved onto Chip McCormick Power Mags for my 1911 and not a single hiccup in 300 rounds.