CMMG 9mm and 22LR Ejection Port Dust Cover Kit with Gas Deflector

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Ideal Ejection Port Cover For 9mm and .22LR with Gas Deflector

The CMMG 9mm Ejection Port Dust Cover Kit is a drop-in replacement for your standard ejection port cover ideal for 9mm or .22LR builds. The kit comes with a steel cover, pin, spring, and polymer brass deflector

NOTE: The included deflector is intended to keep gas and residue out of the shooter’s face during operation. Keep in mind that using it as a brass deflector on anything larger than 9mm is not ideal and can result in damage.

Protects Your Skin & Clothes From Hot Brass

This Ejection Port Dust Cover Kit was designed to be the perfect way to make sure you have a high-quality addition to your build ideal for any shooters, beginners, or professionals.

This enhanced version is thinner and allows greater compatibility with multiple AR-15 upper receivers. The brass deflector redirects empty rounds to one place for easy pickup and also to protect your skin and clothes from hot, discharging brass.


  • Long-lasting and reliable
  • Steel construction
  • Matte black finish
  • Comes with a Deflector Delrin in Black Polymer


  • Ejection port
  • Rod
  • Delrin Brass Deflector
  • Spring

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.

CMMG Warranty

Seller warrants to Buyer that for a period of 6 months from the Delivery Date, all Goods will be:

  • Free from any defects in workmanship, material, and design
  • Conform to applicable specifications[, drawings, designs, samples and other requirements specified by Buyer]
  • Fit for their intended purpose and operate as intended
  • Merchantable
  • Free and clear of all liens, security interests or other encumbrances
  • Not infringe or misappropriate any third party’s patent or other intellectual property rights.

Inspection and Rejection of Nonconforming Goods

The Buyer has the right to inspect the Goods for a period of thirty (30) days after the Delivery Date. Buyer, at its sole option, may inspect all or a sample of the Goods and may reject all or any portion of the Goods if it determines the Goods are non-conforming or defective.

If Buyer rejects any portion of the Goods, Buyer has the right, effective upon written notice to Seller, to:

  • Rescind the Order in its entirety
  • Accept the Goods at a reasonably reduced price
  • Reject the Goods and require replacement of the rejected Goods.


If Buyer requires replacement of the Goods, Seller shall, at its expense, promptly/within 30 days replace the nonconforming Goods and pay for all related expenses, including, but not limited to, transportation charges for the return of the defective goods and the delivery of replacement Goods.

If Seller fails to timely deliver replacement Goods, Buyer may replace them with goods from a third party and charge Seller the cost thereof and terminate this Order for cause pursuant to Section 20.

Any inspection or other action by Buyer under this Section shall not reduce or otherwise affect Seller’s obligations under the Order, and Buyer shall have the right to conduct further inspections after Seller has carried out its remedial actions.

Disclaimer: Manufacturer’s warranty is subject to change without prior notice.

Customer Reviews

Based on 2 reviews
Sean Weirich
I got hairy legs

This was a complete waste of money, the deflector is made of plastic and wobbles around. I'm not sure what the logic was behind this design but its useless. After installing I had to take it off. Ill use the other parts for a future build and repurpose them so its not a complete loss but the deflector is garbage. I could live with it being plastic but the fact that it has play in it and wobbles is beyond me, its only secured by the ejection port rod at the bottom, cheap design cheap part

So sorry to hear that the item did not meet your expectations, Sean. I sent you an email to resolve the issue.

Trevor Lawrenz

CMMG 9mm Ejection Port Dust Cover Kit with Gas Deflector

Thanks for sharing your feedback! We're glad you're satisfied with your purchase.