ˈiːvən ðˌoʊ ðiːz vˈɜːʒənz hæv ðə pˈʊʃpˈɪn hˈoʊl ɪnðə ɹᵻsˈiːvɚ, ðeɪ wɜː ɡɹˈændfɑːðɚd ɪn æz ɐpɹˈuːvd fˈaɪɚɹɑːɹmz ˈæftɚ ðə pˈæsɪdʒ ʌvðə ɡˈʌn kəntɹˈoʊl ˈækt ʌv nˈaɪntiːnhˈʌndɹɪd sˈɪksti ˈeɪt.
Even though these versions have the push-pin hole in the receiver, they were grandfathered in as approved firearms after the passage of the Gun Control Act of 1968.