
AT3™ FU-BAG™ AR-15 Lost Parts Kit – Springs, Detents, Replacement Components
Start your new build the right way – with the best from 1005 Tactical, Magpul, and AT3.
This high quality lower parts kit features all American-made parts from AT3 Tactical including a 2-Stage Nickel Boron Trigger, Magpul MOE Pistol Grip, and an optional Magpul Trigger guard.
End the cycle of countless upgrades to your lower – everything you need for fast, accurate, and ergonomic shooting is right here. At the heart of this kit is AT3 Tactical’s 2-Stage Nickel Boron Trigger, with a total pull weight of only 4.5 pounds. Add to that the quality components you can expect from AT3 and Magpul, and you’re left with an unbeatable value for top quality performance.
American Made Quality
- All parts meet or exceed military specifications (Mil Spec)
- Components are 100% Made in the USA
- Quality packaging keeps components protected and organized
- Backed by the AT3 Lifetime Warranty
This Kit Includes:
- Magpul MOE Grip (With Grip Screw)
- 2-Stage Nickel Boron Hammer
- 2-Stage Nickel Boron Trigger
- 2-Stage Disconnector
- Hammer Spring
- Trigger Spring
- 2-Stage Disconnector Spring
- Hammer Pin
- Trigger Pin
- Bolt catch
- Bolt catch plunger
- Bolt catch roll pin
- Bolt catch spring
- Buffer retainer
- Buffer retainer spring
- Magazine catch
- Magazine catch button
- Magazine catch spring
- Pivot pin
- Pivot pin detent
- Pivot pin detent spring
- Selector
- Selector detent
- Selector detent spring
- Takedown pin
- Takedown pin detent
- Takedown pin detent spring
- Detailed parts diagram included for quick and easy part identification
- Magpul MOE Trigger Guard (optional)
About The 2-Stage Trigger
AT3 has these 4.5 lb 2-Stage triggers made by Schmid Tool Schmid Tool is best known as the premier manufacturer of mil-spec AR-15 fire control groups. From government contracts to the biggest rifle manufacturers – Schmid Tool triggers have been trusted in millions of weapons over their 60 years in business.
Our goal in this partnership is to bring our customers world-class engineering and manufacturing, with factory-direct pricing. For the finest quality triggers you can stake your life on, without the “big brand” price tag.
Check out this great video review from Brian at 704 Tactical!
Have Questions About this Product?

The AT3 Tactical store has a 90 day no-hassle return policy for products in good condition. You can view the full details of our return policy here.
If you encounter an issue or defect with a product after 90 days of your purchase, you can refer to the manufacturer for a warranty claim. Their policies are below.
All AT3 Tactical Brand Products carry a lifetime warranty against manufacturer’s defects.
This includes AT3 Red Dot Sights, Handguards, Iron Sights, and any other product that carries the “AT3 Tactical” or “AT3™” name. For other brands (ex. Magpul or Troy), please refer to the manufacturer’s warranty policy.
In the event that your AT3™ product becomes unusable, we will repair or replace the product at no charge to you.
If we cannot repair your product, we will replace it with a product in perfect working order of equal or better physical condition. The warranty is fully transferable, but we may require information about the original purchase to validate the authenticity of the product.
If your product is in need of warranty service, please contact AT3 Tactical to start the process
Our contact info is available here. To expedite processing, please provide your order information and description of the defect.
Please note: The AT3 Lifetime Warranty does not cover loss, theft, intentional damage or cosmetic damage that doesn’t affect the performance of the product.