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Rock River Arms A4 .450 Bushmaster Completed Upper Up to $60.01 Off w/ Free S&H — 2 models

Rock River Arms Completed Upper Receiver, A4, .450 Bushmaster, 16 Inch Barrel, 1-24 Twist, 5/8-32 Thread ,Free-Float Handguard, Brake, Black, 450B0592
Rock River Arms Completed Upper Receiver, A4, .450 Bushmaster, 20 Inch Barrel, 1-24 Twist, 5/8-32 Thread ,Free-Float Handguard, Brake, Black, 450B0587
Rock River Arms Completed Upper Receiver, A4, .450 Bushmaster, 16 Inch Barrel, 1-24 Twist, 5/8-32 Thread ,Free-Float Handguard, Brake, Black, 450B0592
1 of 2 images
Rock River Arms Completed Upper Receiver, A4, .450 Bushmaster, 16 Inch Barrel, 1-24 Twist, 5/8-32 Thread ,Free-Float Handguard, Brake, Black, 450B0592
Rock River Arms Completed Upper Receiver, A4, .450 Bushmaster, 20 Inch Barrel, 1-24 Twist, 5/8-32 Thread ,Free-Float Handguard, Brake, Black, 450B0587
2 of 2 images
Rock River Arms Completed Upper Receiver, A4, .450 Bushmaster, 20 Inch Barrel, 1-24 Twist, 5/8-32 Thread ,Free-Float Handguard, Brake, Black, 450B0587

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Customer Reviews
Helpful Positive Review Rock River 450 FTW! by Waynard, Verified Owner, December 25, 2024
Dunno what the deal was with the 1 star review I saw the other guy submit. I have had zero malfunctions out of about 80-100rds. Running it on a rifle buffered, ace stocked lower as god intended. Accuracy has been extremely impressive with the hornad...
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2/2 found this helpful
Helpful Negative Review .450 Rock River A4 uppers by Rob- O, Verified Owner, December 15, 2024
Bought 2 uppers and neither of them cycled so I sent them back and got 2 new Uppers and now they are still doing the same thing. Rounds don't eject and bolt doesn't stay open once mag is empty. I am returning these items because it seems like the qua...
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1/1 found this helpful
Most Recent Reviews 450 BM upper receiver by Z, Verified Owner, April 10, 2025
Great upper. Haven't fired it yet but will this weekend. I can't say enough good about Optics Planet. They shipped this fast so it would get to Colorado before our communist tax bill went through. The 2A community is absolutely amazing.
Most Recent Reviews This upper won’t cycle by Dustin Taylor, Verified Owner, March 2, 2025
I’m having issues with mine cycling the has block is aligned right I don’t know what to do it is very accurate but don’t cycle
Read All 4 Reviews
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Product Info for Rock River Arms A4 .450 Bushmaster Completed Upper

If you're browsing for a fantastic offer for the Rock River Arms A4 .450 Bushmaster Completed Upper, then you have come to the right spot..image

Established working with several of the most extremely robust and long lasting substances around, these AR15 Upper Receivers by Rock River Arms offers you an item which gives you many years of stability.

Rock River Arms has been making superior quality products for a number of years, and the Rock River Arms A4 .450 Bushmaster Completed Upper is their particular way of demonstrating just how much they care.

Right here at OpticsPlanet, we ensure that it is our obligation to obtain the perfect product for your needs, and featuring the Rock River Arms A4 .450 Bushmaster Completed Upper is something that we're delighted to offer.

WARNING: California`s Proposition 65

Specifications for Rock River Arms A4 .450 Bushmaster Completed Upper:

Manufacturer: Rock River Arms
Caliber: .450 Bushmaster
Barrel Profile: Standard
Gas System Length: Mid Length
Barrel Twist Rate: 1-24
Threads per Inch: 5/8x32
Handguard Type: Free-Float
Muzzle Device: Brake
Finish: Anadized
Color: Black
Gas Block Journal Size-Diameter: .936 in
Gun Rail: Full Top Rail
Condition: New
Barrel Material: 416R Stainless Steel
Bolt Carrier Group Included: COM-SPEC
Magazine Included: Yes
Mount Type: M-LOK

Package Contents:

  • Rock River Arms A4 .450 Bushmaster Completed Upper
  • Bolt Carrier Group
  • Charging Handle Assembly
  • 5 Round Magazine

Rock River Arms A4 .450 Bushmaster Completed Upper Orderable Models

List of Orderable Models

Rock River Arms Completed Upper Receiver, A4, .450 Bushmaster, 20 Inch Barrel, 1-24 Twist, 5/8-32 Thread ,Free-Float Handguard, Brake, Black, 450B0587 , MPN: 450B0587 , UPC: 842834125531 , Code: 1WN-URC-BFGT-450B0587
Rock River Arms Completed Upper Receiver, A4, .450 Bushmaster, 16 Inch Barrel, 1-24 Twist, 5/8-32 Thread ,Free-Float Handguard, Brake, Black, 450B0592 , MPN: 450B0592 , UPC: 842834125548 , Code: 1WN-URC-BFGT-450B0592

Rock River Arms A4 .450 Bushmaster Completed Upper Unavailable & Discontinued Models

List of Unorderable Models

DEMO, Rock River Arms Completed Upper Receiver, A4, .450 Bushmaster, 16 Inch Barrel, 1-24 Twist, 5/8-32 Thread ,Free-Float Handguard, Brake, Black, 450B0592 , MPN: 450B0592-DEMO , Code: 1WN-URC-BFGT-450B0592-DEMO
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