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Classified Defense - 11.5' - 5.56x45MM - RAT Profile Barrel - Assembly
Classified Defense - 11.5' - 5.56x45MM - RAT Profile Barrel - Assembly

Classified Defense - 11.5" - 5.56x45MM - RAT Profile Barrel - Assembly

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Your Price: $425.00
Part Number: CD-B-11.5-5.56-RAT
Availability: In Stock.
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The goal of Classified Defense has always been to improve existing products to make them better and create new products that make everyone's lives easier. Simply put, we are data driven, extremely analytical, and without a doubt have an extreme case of OCD. 

Most shooters know that bolt action guns tend to have better accuracy over gas guns. There are a few reason why that is. One of the most often overlooked area, in regards to accuracy, is the thermal expansion rate of the barrel. The most heat is generated in the chamber area of the barrel and the heat begins to dissipate the closer it gets to the muzzle.

Most traditional barrel contours are created to be a blend of weight savings and/or attachment points. This causes uneven thermal expansion. The barrels, simply put, get hotter in places with less mass around the bore. That can certainly play a part in the accuracy of the barrel once heat begins to generate. That is why we opted for a custom contour barrel that we are calling our "RAT" profile. RAT stands for Repeatable Accuracy Taper. We want the accuracy of the barrel to be as repeatable as possible to ensure the shots you're sending down range always land in their intended position.

Another large factor in accuracy is the blank and how it is made. We sourced some of the finest barrel blanks available for our barrels. We didn't want to have all the features we have available machined from a shitty barrel blank.

Everyone also knows that chambering and headspace play a large role in accuracy. Sloppy chambers and sloppy headspace will have you chasing your tail while trying to develop accurate reloads and shoot tight groups. We also spared no expense when looking for our barrel manufacturer and their ability to develop an extremely accurate barrel. Our manufacturer isn't some large OEM manufacturer just looking to crank out as many barrels in a day as possible. They are extremely meticulous, methodical, and typically only do custom order stuff. Match grade, world class, barrels is ALL that they do!

Finally, gas system efficiency is a huge part in getting a gas gun to run reliably and softly. Gas port sizing isn't the only variable in the gas system equation. Gas block fitment to the barrel journal and gas tube fitment also play a very crucial role in gas system efficiency. Obviously the barrel journal is spot on from our barrel guy. So we searched for custom gas blocks from a manufacturer that make the best gas blocks. We had no questions as to where we needed to go. So, that is where we went. Again, sparing no expense, we had custom gas blocks made. They may be a bit snug during installation, but the value to having such a precisely made gas block is invaluable. We are also include a coned set screw for use when installing the gas block. We use this screw to align the gas block by tightening it into the dimple under the gas port. Then when you can install the first knurled set screw with Blue Loctite 243. You can then remove the coned set screw and install the second knurled set screw with Blue Loctite 243.

So here you have it. The Classified Defense series of RAT Barrels!

These barrels are considered a Heavy Barrel.

PLEASE NOTE: We strongly recommend cleaning your barrel BEFORE you shoot it. A link to cleaning & break-in can be found below. We also recommend only using Bore Tech Cleaning supplies with Proof Positive Rods, Bushes, Jags, and patches. They make hands down the best cleaning products in the industry. If you aren't already using Bore Tech products, you should be!

  • Manufacturer - Classified Defense & Craddock Precision
  • Barrel Blank - Rock Creek
  • Material - 4150 CMV Steel
  • Caliber - 5.56x45mm
  • Barrel Length - 11.5"
  • Muzzle Threads - 1/2-28
  • Twist - 1:7
  • Gas Block Diameter - .750"
  • Gas System Length - Carbine
  • Gas Port Size - 0.068"
  • Barrel Extension - M4 Feed Ramps Polished Prior to Nitride
  • Barrel Exterior Finish - Nitride
  • Barrel Bore/Chamber Finish - Nitride
  • Contour - RAT - Repeatable Accuracy Taper
  • Bolt Material - C158
  • Bolt Finish - Black DLC
  • Bolt Matched to Each Barrel
  • Gas Block Manufacturer - SLR Rifleworks
  • Gas Block Material - 4150
  • Gas Block Finish - Melonite QPQ
  • Barrel Weight - XX.X oz
  • Gas Block Weight - XX.X oz
What's Included
  1. Classified Defense 11.5" RAT Profile Barrel
  2. Classified Defense Low Profile Gas Block
  3. Classified Defense Matched C158 Black DLC Bolt
  4. Classified Defense Carbine Length Gas Tube
  5. Gas Tube Roll Pin
  6. Gas Block Set Screws - Knurled - x2
  7. Gas Block Set Screw - Coned Tip - x1

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