The Caldwell AR-15 "OOPS" Kit (model 1078425, also sold as the Smith & Wesson M&P or Battenfeld Essentials AR Oops/Field Repair Kit) is a compact spare parts kit designed for AR-15/M4-style rifles. It provides the small, easy-to-lose or damage-prone components (springs, pins, detents, plungers) that commonly go missing during field repairs, builds, takedowns, or maintenance.
It's a "just in case" kit to keep in your range bag, gun safe, or vehicle, helping you quickly get your rifle back online without a trip to the parts store.
Included Parts
The kit typically contains one each of the following mil-spec style components (exact quantities are usually singles unless noted otherwise in variants):
- Bolt catch plunger
- Bolt catch spring
- Bolt catch roll pin
- Buffer retainer
- Buffer retainer spring
- Disconnector spring
- Hammer spring
- Trigger spring
- Hammer pin
- Trigger pin
- Pivot pin detent
- Pivot pin detent spring
- Takedown pin detent
- Takedown pin detent spring
- Selector detent
- Selector detent spring
- Trigger guard roll pin
- Magazine catch spring
These cover the most frequent "oops" moments, such as losing a detent/spring during lower receiver work or breaking a roll pin.
