Radical Firearms 18" .223 Wylde 1:8 S.S. Rifle-Length Barreled Upper - 15" M-LOK RPR Gen3 Rail and BMD Brake

Manufactured by Radical Firearms
SKU: FU18-223W-SS-15RPR-BMD-18
MPN: FU18-223W-SS-15RPR-BMD-18
Manufactured by Radical Firearms
54 Reviews

In Stock

Standard orders will ship out in 1 business day (M-F) if ordered by 3:30 pm CST. FFL orders will ship within 5 business days or less as long as we have the information for the transfer destination. NFA items will take longer to ship and are dependent upon ATF processing times.

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The Radical Firearms 18” .223 Wylde Barreled Upper is a match grade, drop-in solution for your next AR build. Crafted with quality materials and covered by Radical’s lifetime warranty, this better-than-MIL-SPEC upper receiver provides an outstanding solution for any budget. Arrives at your door with the hard work done, just drop in your favorite charging handle, BCG, and sights!

  • 18" 416R stainless steel barrel
  • Chambered in .223 Wylde with 1:8 twist rate
  • 1/2x28 Radical Firearms BMD Muzzle Brake
  • 15" free float Radical Firearms RPR M-LOK Rail
  • Gen 3 rail mounting system
  • Made in the U.S.A.

Includes the lightweight 15" Radical Firearms RPR M-LOK handguard. Crafted from 6063-T6 aluminum and hardcoat anodized a deep black, this tough, durable rail offer a slim, modular profile. Large cooling holes along the rail reduce weight and aid in rapid cooling. Take advantage of M-LOK positions along the 3, 6, and 9 o’clock of the rail for all your favorite gear. An uninterrupted M1913 Picatinny top rail offers space to mount optics, sights, and other accessories with ease.
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Barrel CoatingStainless Steel
Barrel Length18
Barrel LiningStainless Steel
Barrel Material416R Stainless Steel
BrandRadical Firearms
Caliber Gauge.223 Wylde
FinishHardcoat Anodized
Gas System LengthRifle
Gas System TypeDirect Impingement
Handguard15 in Radical M-LOK RPR Rail
Muzzle DeviceRadical Firearms BMD Muzzle Brake
Thread Pattern1/2 X 28
Twist Rate1:8
California Prop 65 warning

 WARNING: This product can expose you to chemicals, which are known to the State of California to cause Cancer and Reproductive Harm. For more information go to www.P65Warnings.ca.gov.

The Good and Bad on my example at least was under gassed


Would give it 5 stars for accuracy but had to do some enlarging of the gas port diameter to have it function as it should. As received had failure to eject spent rounds and jams, last round bolt hold open did not work at all. Removed the forearm and gas block, drilled the gas port to the diameter it should of been according to a port chart I found. That cured the problem, no misfires or jams and bolt hold open works. Cannot complain about the accuracy

Great deal!!


This is a nice upper, the handgaurd leaves alot to be desired but the thing can shoot! I used to buy all BCA stuff but after getting 6 bad barrels in a row it was time to switch. It is a little under gassed but never a problem cycling. I would give it 4 stars but for some reason it won't let me click on the 4th star, the handgaurd keeps it from being 5 stars.

Looks good but didn't cycle a new round

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I bought this two weeks ago. Upper looked good. Rail has aggressive corners and might be uncomfortable for some. It's not bad for my hands plus I added a Harris bipod so I won't be handling the rail too much.

Upper looks good has a keyhole marking for those that care. Its heavy.

Onto my rating.

I swapped uppers on a poverty pony with PSA BCG which ran great with a PSA carbine upper.

First shot it would not cycle a new round. It fired it just fine but I had to manually cycle a new round.

I thought it might be an ammo issue. Tried 3 different brands including match ammo and still same issue.

Not sure what to do now. I like the look of the upper but sucks it doesn't work. Perhaps an under gassed issue or a gas block misalignment.

Accurate !!


This is a very accurate and reliable upper, dont hesitate

Excellent impulse buy.

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Bought this on an impulse on the last sale and I am very pleased. Finally had a chance to take it out last weekend to break it in, first time I have ever done that. Initially the bolt was not locking to the rear by about the 50th round it started to operate as expected (locking). My groups began to get smaller and I think the barrel is more accurate than I am. :) Looking forward to seeing what I can do with it. Delivery was spot on keep up the good work PA, saving up for an optic.

Great Shooter for Low Cost


Got this upper back in June. It does shoot surprisingly well for the low cost. I’ve shot 55 gr and 62 gr bullets through it and was consistently hitting an 8” plate at 300.

Great Upper!

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I purchased this upper because I was looking for an 18" .223 Wylde upper for the obvious advantages of the Wylde chamber, the increased accuracy and velocity of the 18" barrel, and the improved cycling of the rifle-length gas block. This upper fit the bill without breaking the bank. I wanted to take my rifle being a primarily close-range carbine to an all-purpose rifle. I was even able to recover about 90% of the cost by selling my old upper, essentially breaking even!

I've shot probably about 200 rounds through it and it has worked pretty much flawlessly so far. I had one malfunction early on, which I attribute to just breaking in, but it has been flawless after that. It seems quite accurate with Winchester white box 5.56, more so than with the .223, but maybe that's just me or the cheap .223 I was using.

Overall, it was a great buy as far as I can tell without doing any crazy stress or accuracy testing.

Execellent value, functions as advertised.

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I have received a prize. This is beautifully executed and it works as advertised. NO under gassed anything. I had cleaned and added a bit of CLP to the bolt before firing. I put it on a DPMS lower this morning and burnt thru 30 rds with no problems at all. Would have bought more if I had the money.

Great price can't go wrong...

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First of all Thanks everyone at PA place my order 10 minutes before cutoff time and still managed to send it the next day. Received my Radical Firearms 18" SS Wylde today very good deal more upper receiver for the price I missed their weekend sale so all gone, patiently waited until their back on stock. This will go to my new build my version of Cheap SPR.

ps. Thanks for the Beanie hat just in time for the next cold front.

Good quality, incomplete assembly

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Shipping was very fast but unfortunately I cannot give this a very good rating. Upon opening the box and inspecting the upper everything looked good except that I noticed that the gas block did not have any screws in it! Imagine if someone received this and just threw it on their lower and tried to shoot it. Dangerous. Wouldn't be good. Got into contact with customer service and all they could say is sorry and that they have so many uppers that they cant inspect every single one. Not very good quality assurance to me. But they did contact radical firearms to send me the hardware. And when I finally get the screws, I'm going to have to take the handguard off and correctly install the gas block. I personally would give this a lower rating but since they were responsive to my issue i bumped it up a little more. I will definitely have a lower rating for radical firearms for sending out incomplete uppers. Well see how long it takes before I can even shoot this.