The three Glock MOS models that will be available 2015 will include the Practical Tactical Gen 4 G34 (9 mm), Gen 4 G35 (.40 S&W), and the new long-slide Gen 4 G40.

The Glock 19 Gen4 is designed for function first. This design philosophy means that the gun parts fit together more loosely than most, making it not as accurate as competition-level pistols.

The Glock 19 Gen4 is designed for function first. This design philosophy means that the gun parts fit together more loosely than most, making it not as accurate as competition-level pistols.

The G17 Gen5 MOS and the G19 Gen5 MOS will be available for purchase starting Oct. 5, 2018 at participating dealers. For additional information about Glock Modular Optic ready pistols, visit glock.us.

The company is introducing Glock models 17 and 19 Gen. 4 MOS, for Modular Optic System, at this year's SHOT Show, according to Kyle Hopp, commercial manager for Glock.