The Midwest Industries AR Drop-In Trigger Kit with Lower Parts (Midwest Industries part no. MI-TRIGGER-KIT-C) bundles a complete 3.5 lb single-stage trigger system with a full set of AR lower parts, including an ambidextrous safety selector, in a self-contained cassette housing that installs with no fine-tuning required. Interior parts are S7 tool steel, heavy-hit hardened, and finished in black nitride for strength and corrosion resistance, while the cassette housing itself is blue anodized aluminum. It’s built for shooters who want a crisp, lightened trigger pull and a full lower parts refresh in a single order rather than sourcing individual components.

Key Specifications

• Delivers a 3.5 lb single-stage trigger pull with an ultra-smooth, crisp break.
• Features quick reset and low overtravel for faster follow-up shots.
• Interior parts are S7 tool steel, heavy-hit hardened and finished in black nitride.
• Cassette housing is blue anodized aluminum and weighs approximately 2.4 oz.
• Fits small pin size (.154) and works with most .223 and .308 AR-style platforms.
• Includes an Ambi Safety Selector with a 60/90-degree option.
• Includes a full set of lower parts: bolt catch assembly, mag catch assembly, buffer retainer assembly, takedown pins and detents, and a Magpul MAG417 trigger guard.
• Backed by a limited lifetime guarantee and made in the USA.

Frequently Asked Questions

What rifle platforms does this kit fit? Most .308 and .223 AR-style platforms with a small pin size of .154.

What lower parts are included beyond the trigger? A full set including bolt catch, mag catch, buffer retainer, takedown pins and detents, and a Magpul trigger guard.

Can I adjust or modify the trigger’s internal set screw? No, the center set screw should not be tampered with, as doing so voids the warranty.

Buy the Midwest Industries AR Drop-In Trigger Kit with Lower Parts, Black

Instead of sourcing a trigger and lower parts kit separately, this Midwest Industries kit gives you both in one self-contained, no-fitting-required package. Order it from our Lubbock, Texas gun shop for fast, insured shipping, and browse our full AR lower parts kits selection.