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18" 450 Bushmaster Upper Assembly AR 15 Rifle Length Rail
18" 450 Bushmaster Upper Assembly AR 15 Rifle Length Rail

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List Price: $489.99
Our Price: $269.99
Savings: $220.00

Availability:: Usually Ships in 24 to 72 Hours
Product Code: 18450CMU1X24RLMLR

Add A Magazine*:

Choose A Different Muzzle Device*:

Choose Keymod or M Lok Slots*:

Bolt Carrier Group:

Charging Handle:

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Description Additional Info

18" 450 Bushmaster Upper Assembly AR 15 Rifle Length Rail

*Milspec forged aluminum upper receiver with forward assist and dust cover assembly installed. Matte black hard coat anodized Mil 8625 Type 3 Class 2. One large single Feed Ramp for big bore cartridges. Forged from 7075 T6 aluminum. This receiver has been correctly modified around the ejection port to allow for clearance and proper ejection of the 450 Bushmaster cartridge.

*12" Rifle Length Narrow Profile Free Float Rail. Very comfortable and very light weight. Your choice of Keymod or M Lok slots. Slots run the entire length of our rail at the 3, 6, and 9 o'clock postions. Picatiny rail sections NOT included but are available for purchase on our website if needed. Rail sections easily attach to our rails for adding accessories like bipods, flash lights, grips, lasers, etc.

*18" 450 Bushmaster 4150 Hardened Chrome Moly Steel Barrel with 1x24 twist. Heavy Contour with 5/8x32 muzzle threads. Proper single feed ramp for 450 Bushmaster cartridge. Parkerized finish.

*.750 low profile gas block.

*Mid Length Gas Tube.

*Compact competition muzzle brake with crush washer.

*This upper assembly will fit all standard AR 15 lower receivers.

This item IS NOT A FIREARM!!! It is only "Firearm Parts", so no FFL is needed and it can be shipped directly to you. You are responsible for knowing your state or local laws. We will not ship this item to areas where it is not legal to own..

Average Rating: Average Rating: 5 of 5 5 of 5 Total Reviews: 20 Write a review »

  0 of 0 people found the following review helpful:
5 of 5 450 upper December 21, 2019
Reviewer: Jason  
Very good upper. Swapped out from my 556 to those and it shot very good group right off
the bore sight

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  0 of 0 people found the following review helpful:
5 of 5 450 Bushmaster Upper November 19, 2019
Reviewer: AE from BROOKINGS, SD United States  
I love this upper.  Quality product, tack driver.  Price was good very affordable and was delivered in 3 days!  I will be recommending this product to friends.

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  1 of 2 people found the following review helpful:
5 of 5 18" 450 Bushmaster upper, BCG, CH, Mag October 14, 2019
Reviewer: Travis Edris from Selah, WA United States  
I have been researching this round and buying a rifle chambered in 450 BM for longer than I'd like to admit. I finally, through the most ridiculous and exhaustive search and study, purchased an upper, BCG, CH and mag through AR15part. I was really happy with how fast it shipped, and was doubly happy with the quality of the parts.  I was however skeptical of the reports of "one ragged hole" at 100 yds. I was also mildly concerned of feed and extraction issues. I waited until multiple range days to make this review and if you read nothing else: This thing SHOOTS! I am amazed at the accuracy, craftsmanship, and it cycles flawlessly! I will be buying from these guys again soon. Travis Edris out.

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  1 of 1 people found the following review helpful:
4 of 5 Good quality & Excellent Power August 22, 2019
Reviewer: Michael Smith from Norton Shores, MI United States  
Awesome upper.  Seems very accurate.  I have had this for a few weeks now and it is extremely well constructed.  However, it was very difficult to remove the muzzle brake.  I had to heat the barrel with a torch and torque on it.  Also, I am still experiencing cycle issues with this rifle.  It fires fine, but won't strip the next round from mag 90% of the time.  I contacted seller who suggested drilling the gas port out to 3/32.  Still no luck, and the bolt does not kick all the way back on last round.  It seems to lock back, just not all the way back.  Anywho, its a very nice upper and I will probably try an adjustable gas block next.

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  0 of 0 people found the following review helpful:
5 of 5 450 BM May 10, 2019
Reviewer: JUSTIN K from montpelier, OH United States  
I received a 450 bushmaster upper 3 days after I ordered it and it looks and shoots great. Thanks.

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