AT3™ FU-BAG™ AR-15 Lost Parts Kit – Springs, Detents, Replacement Components

Made an “Oops” with your New Build?  You Detent-Launchin’, Spring-Losin’ Fool, you.

We’ve all been there.  Whether it’s rolling the dice on that bargain bin LPK in your local gun shop, launching a detent across the garage, or losing a spring to the shag carpet in mom’s basement, you’re missing a part or two.  The situation is FUBAR, and you’ve F***ed Up – Building A Gun.

That’s why we’re offering the FU-BAG!  The handy bag of commonly lost lower parts, plus a couple of gas tube roll pins and an adhesive bandage.  Whatever happy little accident you’ve managed to make, we’ll help you patch it up with this bag of goodies.

Except if you jettison a detent or spring directly into your eyeball or something.  Always wear eyepro, guys.

If you need more parts for a seriously messed up situation, check out the Motherfu-Bag!  It includes more parts on the bolt that commonly break or wear out, plus spare springs and for the fire control group.

American Made Quality

• All parts meet or exceed military specifications (Mil-Spec)
• Components are 100% Made in the USA
• Backed by the AT3 Lifetime Warranty

The FU-BAG Includes:

• Bolt catch plunger
• Bolt catch roll pin
• Bolt catch spring
• Buffer retainer
• Buffer retainer spring
• Magazine catch spring
• Selector detent
• Selector detent spring
• (2) Takedown/Pivot pin detent
• (2) Takedown/Pivot pin detent spring
• Trigger guard roll pin
• Mil-Spec Disconnector Spring
• (2) Gas Tube Roll Pins
• (1) Adhesive bandage for any other boo-boos you make

Products available on this page:

• AT3™ FU-BAG™ AR-15 Lost Parts Kit - Springs, Detents, Replacement Components - Quantity: Single  |  SKU: AT3-FU-BAG
• AT3™ FU-BAG™ AR-15 Lost Parts Kit - Springs, Detents, Replacement Components - Quantity: 3-Pack  |  SKU: AT3-FU-BAG-3PK

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.