Aero Precision Replacement Spring / Detent Oops Kit (AR-15 / AR-10)

Aero Precision Replacement Spring / Detent Oops Kit (AR-15 / AR-10)

Product Code:
Calculated at Checkout

MPN: APRH101627


  • Fits all standard lower receivers
  • Features the most commonly lost parts
  • High quality with competitive pricing


  • AR-15, AR-10, M4E1 and M5


  • 2x Bolt Catch Roll Pin
  • 2x Buffer Retainer
  • 2x Buffer Retainer Spring
  • 2x Safety Selector Detent
  • 2x Safety Selector Detent Spring
  • 4x Pivot/Takedown Pin Detent
  • 4x Pivot/Takedown Pin Detent Spring
  • 2x Trigger/Hammer Pin
  • 2x Disconnector Spring
  • 2x 4-40 Set Screw (for threaded takedown in detent hole)


The Aero Precision oops kit is a necessity for the shooting bag of all AR15 owners who want to take their preparedness to the next level.

The Aero Precision Oops Kit Comes In Handy At The Shooting Range

This AR oops kit includes parts that are commonly broken or misplaced. Next time you are at the range and you experience a break, by having this kit in your shooting bag, you can be back to practicing in minutes.

The Aero Precision Oops Kit Is Useful At Home

When you are cleaning your AR-15 at home after getting in some range time, if you lose a piece you will be able to reassemble your weapon immediately. This helps you achieve optimal defense readiness and allows you to search for the missing part when time permits.

Should you be building an AR15, this kit is also great to have available; you never know when you might need an extra part.

What AR-15s Are Compatible With This AR Oops Kit?

Aero Precision manufactured this kit for the .300 Blackout and the 5.56x45mm AR15. The parts included in the kit are also compatible for M5 and M4E1 builds.

Write a Review

21 Reviews

  • Will buy again

    Posted by Bobby on 30th Apr 2020

    Great quality

  • Great product

    Posted by Mat mc on 25th Apr 2020

    great insurance to have around when you shoot a takedown pin detent spring across the room

  • Good project

    Posted by Bobby on 19th Apr 2020

    Great product! Fast shipping!

  • everything i needed

    Posted by Bob on 12th Apr 2020

    shipped fast

  • spare parts kit

    Posted by Albert Dodd on 9th Apr 2020

    great parts selection especily the two screws that are needed to put together aero enhanced lower

  • spring and detent kit

    Posted by Shawn on 6th Apr 2020

    Everything works great and they give you a decent amount of parts for the price. I would rather see a couple other parts instead of the trigger pins. I usually get them with the trigger already. Would be nice if the plunger and spring for the bolt catch were included.

  • I haven't used it but it looks like a well thought out kit. Nice to have around

    Posted by David Foster on 9th Feb 2020

    I would by again


    Posted by Joshua Dahn on 5th Feb 2020

    Bought this because no one seems to include pins/springs when you buy "Enhanced" lower parts. and now I'll be buying another just to keep the parts on hand. There are other companies that have these kits but I'm glad a company I'm familiar with offers the kit.

  • Great common AR parts kit at a great price!

    Posted by Manny M on 4th Feb 2020

    I recently purchased a Geissele AR lower parts kit and was in the process of building an AR platform when I suddenly realized the Geissele kit was missing a single plunger pin. I thought about calling Geissele about it but imagined how much more hassle it would be dealing with this issue through them than just buying the oops kit from Aero Precision, so I ordered one. It arrived soon after I ordered it and I was able to pull from the kit the plunger I was missing and quickly finish the build. The kit comes with two each, of the most commonly lost or misplaced pins, plungers and springs of an AR build. The springs and pins visually appear to be well finished and of great quality, however some of the plunger pins appear to have small imperfections which could lead to malfunctions or rough operation but since there are two of each, you can pull the ones with the best finish or try to polish or correct the ones that are a bit rough around the edges. All in all, you cannot beat the Oops Kit in a pinch, it is an absolute life saver and a fantastic product offering by Aero Precision!

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