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CMMG 300 AAC Blackout 16.1″ Barrel – Carbine Length 1:7 Twist – 4140 CrMo Salt Bath Nitride

Only 13 Remaining

90 Day No-Hassle Returns We Pay Return Shipping

We have a 90-day no-hassle return policy. We pay return shipping.

If you need to request a return, contact us at support@at3tactical.com and we will send you a return label

After 90 days, defective items will still be covered under the manufacturer’s warranty, where applicable.

Please refer to the product listing for warranty details. If you have specific warranty questions, contact us at support@at3tactical.com. We may direct you to pursue your warranty claim directly with the manufacturer.

Your satisfaction is our #1 priority

If you’re dissatisfied with your purchase, in any way, please contact us at support@at3tactical.com – we will do our best to make it right.

Fast & Free Shipping On orders over $50

You will receive fast, free shipping for all orders over $50

Shipping cost is $7.99 for orders under $50. We ship with UPS or USPS, depending on the item.

Most orders received by 1pm CST ship the same day

You will receive an email with tracking information at the time of shipment. To expedite shipping, we may ship your order from multiple warehouses. Orders placed on weekends, holidays, or after 1pm will ship the following business day.

Perfect for building your custom AR15 upper group. Comes with properly installed M4 barrel extension. All barrel sub-assemblies are properly headspaced.


  • 16.1?
  • Multi Role Profile
  • 4140 Chrome Moly
  • Salt Bath Nitride Finish inside and out
  • 1:7 Twist
  • 300 AAC Blackout Chamber
  • Threaded 5/8-24
  • Carbine length gas port
  • .750? Gas Journal

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Customer Reviews

Based on 1 review
Good barrel, Better Company to Buy From.

Barrel works as advertised. Not a $300 barrel, so it probably won't last through 100k rounds, but it's exactly what I needed. The biggest reason for 5 stars is just AT3 Tactical, hands down the best customer service I've come across building AR's from the internet. Had a problem with a defective product, let them know, received a response within 3 hours, they sent out a new one, and a return box for the defective one. You can buy from these guys with all confidence that you'll be satisfied or they'll make it right. The pic is sighting in with AT3's 2 MOA Red Dot firing 3 round groups, and checking placement. 75 yds with 1X optics, I'm more than satisfied with everything AT3 Tactical.