MPN: 38CA61A


  • CMMG MK3 Gun builders kit includes most of the necessary parts to build up your lower group except the commonly upgraded parts
  • Compatible with CMMG Mk3 Lowers and most LR308 type lowers
  • All parts meet or exceed Mil-Spec


  • Material: Steel
  • Finish: Black


  • CMMG MK3 Lowers and most LR-308 type lowers


  • 1x .308 Bolt Catch Screw
  • 1x .308 Pivot Pin
  • 1x .308 Take Down Pin
  • 1x Bolt Catch
  • 1x Bolt Catch Buffer
  • 1x Bolt Catch Spring
  • 1x Buffer Retainer Pin
  • 1x Buffer Retainer Spring
  • 2x Trigger Hammer Pins
  • 1x Magazine Catch
  • 1x Magazine Catch Button
  • 1x Magazine Catch Spring
  • 1x Safety Selector
  • 1x Safety Selector Spring
  • 1x Safety Selector Detent
  • 2x Take Down / Pivot Pin Detents
  • 2x Take Down / Pivot Pin Detent Springs


When you’re assembling an AR, one of the first things you’ll want to consider is the quality of the products you intend to use. Cheap or faulty parts can make your life miserable if they should fail you when you need them most.

If you’re looking for a high-quality lower parts kit for your CMMG MK3 or LR-308, consider this CMMG MK3 Gun Builders Kit. CMMG was founded over 20 years ago by four members of the Overstreet family. The business has increased in size each year and is always on the lookout for ways to improve its products and customer satisfaction. Each and every rifle or firearm part sold by the company is manufactured in the United States from materials of the highest possible quality.

This LR-308 Gunbuilder Lower Parts Kit provides all the small, Mil-Spec parts that are often required in an LR-308 build. This kit permits you to choose the aftermarket upgrades of your choice for your AR, including the pistol grip and the trigger. Unlike similar AR10 LPKs, this kit allows you to customize your firearm without wasting money on parts you never intend to use. All pieces of this LPK meet or exceed Mil-Spec standards to give you many hours of trouble-free operation.

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