Expo Arms AR-15 Upper Receiver Parts Kit

Manufactured by Expo Arms
Manufactured by Expo Arms
15 Reviews

In Stock

NOTE: Limit 3 per household. Quantities exceeding 3 will not allow checkout.

We are fully staffed and processing orders. Standard orders are shipping in approximately 1 business days or less. FFL orders take approximately 10 business days or less if you can provide us an actively receiving FFL location. Due to high demand, there is a limit of 5 FFL items in a 30 day period.



The Expo Arms AR-15 Upper Receiver Parts Kit contains the small parts you need to assemble a MIL-SPEC stripped upper. Each kit contains a standard ejection port cover assembly and forward  assist assembly with appropriate pins and springs, and even features a spare C-clip. Proudly made in the U.S.A.

  • Forward Assist
  • Forward Assist Spring
  • Forward Assist Retaining Pin
  • Ejection Port Cover Door
  • Ejection Port Cover Pin
  • Ejection Port Cover Spring
  • Ejection Port Cover C-Clip
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BrandExpo Arms
TypeUpper Parts Kit

WARNING: This Product can expose you to chemicals which is known to state of California to cause Cancer and Reproductive Harm. For more information, see www.p65warnings.ca.gov

Awesome service good kit

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Fast shipping got my parts within 4 days upon receiving the dust cover detente was bent I call customer service and they sent a whole new kit!!! very impressed with the service of the company

Excellent quality upper parts kit!

by -

As good a quality upper parts kit as I've used. All parts were a nice black coloring, solid, and excellent fit and function. Bonus c clip included.

Decent quality, missing a part

by -

I didn’t have high expectations for this kit, it would have been five stars if it actually came with the roll pin.
<br>From PA: We sent a couple of roll pins out to you when we saw this. Sorry about that!

Ejection port cover to large

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Seems like it would be okay other then the fact that they gave me a dust cover about 1/8 inch larger then normal so it wouldn’t fit my upper for ar15, I think they gave me a 308 parts kit idk.

Will not fit Anderson Upper Receiver

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I purchased this for the Bear Creek Arsenal 16" SS 5.56 barrel that came with an Anderson Arms Stripped upper receiver. Allo the upper kits claim to be standard but this one will not fit the Anderson Upper Receiver as the door is too large. Someone needs to know what STANDARD is! At least offer an ANDERSON kit to go with the stripped Upper and note that that is the onbly one that fits it. Hoping to get a replacement but is should not have happened in the first place.

Dust cover will not fit Anderson Upper.

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Same issue as previously reported. Will not fit the Anderson Upper. I have not tried any other uppers as that is all i have right now.

New dust cover received

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Update on a previous review. They sent a new dust cover ASAP. Good way to keep customers and keep them happy too. Thanks PA.

Good price

by -

Good product for the price. Everything fit good and functioned well.

expo upper parts


installed on a Ceratac upper. fit great, no issues

Buy a different kit...

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The ejection port cover would not latch on an Aero Precision upper at all and looks as if it's already been through combat. Would definitely not buy again due to the cover, but the rest of the parts were ok.
<br>From PA: Very sorry to hear this! We'll be happy to send you a replacement.


by -

Junk, forward assist spins loosely in Aero upper and no C clamp for ejection port cover.
<br>From PA: We're very sorry that you received a bad UPK. One of our CS reps will reach out to you to take care of this.

Fits Anderson upper

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I ordered an Anderson upper and this parts kit from Primary Arms at the same time. Assembled everything in about 5 minutes. Do make note that the dust cover fits snug, but You use a punch or even the end of a pen and work the detent 10-20 times, the spring softens up and works great. Not much to say other than that. It’s basic, and it works great. No slop with the forward assist.

Do not buy this kit!

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I should have heeded the cautions in the other negative reviews and not purchased this kit. I am very disappointed in the function of the forward assist. It rotates excessively such that I am concerned it may not engage the serrations on my carrier fully and could cause damage. Also, and more importantly, it does not retract all the way when I press and release it. I am will not finish my build with these parts as I am seriously concerned about safety issues if the FA catches on the carrier during the firing cycle. I will be seeking a replacement FA. I gave two stars because the dust cover appears to be OK.
<br>From PA: We're sorry that you received a bad kit and we'd be happy to swap it out for you.

Would be better with all listed parts

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Bought with stripped anderson upper,foward assit fits a little tight,dust cover is adequate but did not come with c clip for dust cover pin

Good deal

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Looking for a great deal, this was it, on sale bought several. Finding the horseshoe clip for the dust cover rod can be a trip. If its loose in the bag, (parts are very nicely separated by function and triple bagged) not a problem, but if you think you didn't get one. Check the dust cover vary closely it will be stuck on the surface somewhere by oil tension. Had a photo to show but not available here. The forward assist held in by a roll pin, usual roll pin issues but not a product problem. The product picture shows two horseshoe clips, but you only get one if you can find it. One of the dust cover latches was hard to close after assembly, but working it several times fixed it.