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Questions & Answers
What is the twist rate of this Upper? Expert Answer

The twist rate is 1:14.

by Jonathan D., Gear Expert, April 22, 2018
Do models that say they have a 20” barrel...actually have a 20” barrel? Does Radical have an answer for the fail to feed and extract issues? Thanks. Expert Answer

Yes, the barrel will be 20". Unfortunately, you will need to contact Radical Firearms about any modifications have been made to correct issues.

https://www.radicalfirearms.com/Contact_Us_a/83.htm

by Kurt Colbourne, Gear Expert, September 14, 2021
Customer Reviews
Helpful Positive Review
450 Bushmaster complete upper by Pickalo, February 18, 2018
Very easy to order. Product operated perfectly. Was able to track shipment and new when it was going to arrive. I would recommend radical firearms 450 Bushmaster complete upper to any one. The pricing was very comparable and shipping was great. Getti...
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1/2 found this helpful
Helpful Positive Review
450 Bushmaster upper by Jesse, December 14, 2017
For the price of this upper I was a little concerned that the quality would not be there. I'm glad to say I was wrong. This is a great upper at a great price. Had it sighted in with 6 shots and killed a deer with the 7th. I definitely recommend this ...
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8/8 found this helpful
Helpful Positive Review
20 450 bushmaster. Lots of fun. by Skipper, Verified Owner, November 6, 2017
My 3rd Radical Firearms upper. So far so good. BCG is a bit tight but should break in in a few more boxes of ammo. This IS a round you want to reload since finding factory ammo is kind of hit and miss. Recoil is pretty much a lot less than I was expe...
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4/4 found this helpful
Helpful Negative Review
Fails to Extract - Hard locked bolt by Ray, Verified Owner, November 24, 2017
Received the upper after some delay (10 weeks). Fits well on the lower, bolt is a little stiff, but workable after cleaning. Firing at the range, it is very accurate. However, the fired cartridges will not extract, basically have to disassemble the r...
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8/8 found this helpful
Most Recent Reviews
Good upper for the price. by Rusty Longiron, March 3, 2019
Just finished assembling the rifle. Gave it just a quick test fire off the deck. It fed, fired and ejected which is a good start. I had to use a standard 20 round 223 mag because for reasons I'm still waiting to find my upper did not have the 450 mag...
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0/1 found this helpful
Most Recent Reviews
Wouldn’t eject shells by Backfat, Verified Owner, November 13, 2017
I shot 2 boxes and it never ejected 1 shell. Sent it back and went with a different brand. Took a full 20 days to get and then it didn’t even work . I almost missed my hunting season waiting for this and then it not working and waiting for a new o...
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1/4 found this helpful
Read All 11 Reviews
Caliber: .450 Bushmaster Barrel Length: 16 inGas System Length: Mid Length Barrel Twist Rate: 1-20 Threads per Inch: 5/8x32 Handguard Type: Free-Float Muzzle Device: Panzer Brake Finish: Anodized Color: Black Model: 15in First-Gen Hybrid Rail System - FHR Gas Block Journal Size-Diameter: .936 inHandguard Length: 15 inHandguard Style: Hybrid Rail Gun Rail: KeyMod , M-LOK Condition: New Magazine Included: Yes Length: 16 in, 25.5 in

Code: 2CS-URC-CUA450-CFU16-450BUSH-15FHR

MPN: CFU16-450BUSH-15FHR

UPC: 816903027439

Product No Longer Available

Product Info for Radical Firearms Complete Upper Assembly .450 Bushmaster, 15in MHR, Single Ramp, Black, Box

Get a high powered firearm that will deliver your tightest groupings yet when you build your rifle with the Radical Firearms Complete Upper Assembly .450 Bushmaster. These AR15 Upper Receivers by Radical Firearms come complete and assembled so that you don't have to fidget around with parts or waste time building. The Radical Firearms Upper Assembly w/ MHR comes with an upper receiver, forward assist, custom ejection port door, barrel nut, 16in 450 Bushmaster barrel, Panzer muzzle brake, bolt carrier group, charging handle, and a 450 Bushmaster mag. You won't find a better collection of parts for this great of a value anywhere else on the market. Plus, you can utilize the M-LOK attachment points on the sides and bottom or the Picatinny rails at the fore end to mount optics, lasers, lights, bipods and other accessories to customize your rifle to its fullest potential. Pick up your Radical Firearms .450 Bushmaster Full Upper Assembly today to build a powerful rifle that will deliver optimum performance for life.image

Features of Radical Firearms Complete Upper Assembly .450 Bushmaster, 15in MHR, Single Ramp, Black, Box:

  • Barrel Profile: Big Bore Profile
  • Barrel Material: 4140 Chrome Moly Vanadium
  • Barrel Finish: Melonite
  • Barrel Extension: Single Feed Ramp
  • Gas Block Type: .936 Low-profile Gas Block
  • Upper Receiver Material: Forged 7075 T6
  • Upper Receiver Style: M4 MIL-STD with Oversized Ejection Port
  • Upper Receiver Finish: Type III Anodizing
  • Forward Assist: Yes
  • Dust Cover: Yes
  • Charging Handle: MIL-STD
  • Bolt Carrier Group Included: Yes
  • BCG Finish: Nitride
  • Magazine: 450 7 Round

    * Includes 1 Magazine

Package Contents:

  • Radical Firearms Complete Upper Assembly .450 Bushmaster, 15in MHR, Single Ramp, Black, Box

Ammunition

116 / 16
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Radical Firearms Complete Upper Assembly .450 Bushmaster, 15in MHR, Single Ramp, Black, Box Unavailable & Discontinued Models

List of Unorderable Models

  • Radical Firearms Complete Upper Assembly 16in .450 Bushmaster, 1/14 Twist, 15in FHR, KEYMOD, Black, CFU16-450BUSH-15FHR , MPN: CFU16-450BUSH-15FHR , UPC: 816903027439 , Code: 2CS-URC-CUA450-CFU16-450BUSH-15FHR
  • Radical Firearms Complete Upper Assembly 20in .450 Bushmaster, 1/14 Twist, 15in FHR, KEYMOD, Black, CFU20-450BUSH-15FHR , MPN: CFU20-450BUSH-15FHR , UPC: 816903027446 , Code: 2CS-URC-CUA450-CFU20-450BUSH-15FHR
  • DEMO, Radical Firearms Complete Upper Assembly 20in .450 Bushmaster, 15in MHR, Black, CFU20-450BUSH-15MHR , MPN: CFU20-450BUSH-15MHR-DEMO , Code: 2CS-URC-CUA450-CFU20-450BUSH-15MHR-DEMO
  • Radical Firearms Complete Upper Assembly 20in .450 Bushmaster, 15in MHR, Black, CFU20-450BUSH-15MHR , MPN: CFU20-450BUSH-15MHR , UPC: 816903027989 , Code: 2CS-URC-CUA450-CFU20-450BUSH-15MHR
  • Radical Firearms Complete Upper Assembly 16in .450 Bushmaster, 15in MHR, Black, CFU16-450BUSH-15MHR , MPN: CFU16-450BUSH-15MHR , UPC: 816903027309 , Code: 2CS-URC-CUA450-CFU16-450BUSH-15MHR
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