July, 23

AR-15 40 S&W Complete Upper: The Ultimate Guide for Upgrading Your Rifle

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Are you looking to upgrade your AR-15 with a complete upper? Then look no further than the AR-15 40 S&W complete upper. This powerful upper provides increased accuracy, range, and stopping power for your rifle.

The .40 S&W round is known for its impressive ballistic performance and is commonly used by law enforcement agencies due to its ability to deliver superior results in self-defense or tactical situations. When combined with an AR-15 platform, this caliber becomes even more effective thanks to the increased accuracy and range provided by the rifle's longer barrel.

If you're serious about enhancing your firearm's capabilities, then it's time to consider investing in an AR-15 40 S&W complete upper. In this article, we'll take a closer look at what makes these uppers so special and why they're becoming increasingly popular among gun enthusiasts. So keep reading if you want to learn more!

AR-15 40 S&W Complete Upper: The Ultimate Upgrade for Your Rifle

If you're a gun enthusiast looking to upgrade your AR-15 rifle, the 40 S&W complete upper is an excellent option. This conversion kit allows you to use .40-caliber rounds in your rifle, which can provide better accuracy and stopping power than other calibers.

In this article, we'll explore the benefits of using an AR-15 40 S&W complete upper and provide tips on how to choose the best one for your needs.

What is an AR-15 40 S&W Complete Upper?

Before we dive into the specifics of this upgrade, let's first define what an AR-15 40 S&W complete upper is. In simple terms, it's a conversion kit that replaces your current upper receiver with one that's designed specifically for .40-caliber rounds.

The kit typically includes everything you need to make the switch, including a new barrel, bolt carrier group (BCG), charging handle, handguard/rail system and muzzle device. With all these components working together seamlessly as part of a single unit or package – "complete" – installation is relatively easy.

Once installed on your rifle lower from any reputable manufacturer such as Colt Defense or Bushmaster Firearms International LLC., it provides greater versatility in terms of different ammo types available at varying price points without sacrificing performance or reliability whatsoever!

Benefits of Using an AR-15 40 S&W Complete Upper

Now that we know what exactly this upgrade entails let's discuss some benefits associated with its use:

Improved Stopping Power

One significant benefit associated with using .4o caliber ammunition in rifles like our beloved ArmaLite Rifle model number fifteen (AR)-fifteen has been its ability noted by many shooters just like yourself worldwide who appreciate firearms' finer qualities: improved stopping power compared even against higher caliber options such as 9mm or .45 ACP.

Enhanced Accuracy

Another benefit is the enhanced accuracy at longer ranges due to a larger bullet size. This is especially true if you're using a high-quality barrel that's been specifically designed for this caliber. The heavier and larger bullet of the 40 S&W will have less wind drift and better ballistic coefficients compared to smaller calibers, so it's an excellent choice for precision shooting.


Lastly, using an AR-15 40 S&W complete upper provides greater ammo versatility as mentioned earlier: in addition to being used with standard FMJ rounds, hollow points can also be fired from these uppers which are more effective against softer targets like human flesh or animals. And since .4o caliber ammo isn't as popular amongst shooters compared some others like 9mm Luger or .223 Remington there are often deals online offering lower prices per round cost-wise thus further providing feasible option when on tight budget!

Choosing the Best AR-15 40 S&W Complete Upper

When choosing your ideal conversion kit keep in mind that not all products are created equal! Here's what you should look out for:

  • Quality materials: Look for components made from reputable manufacturers who use high-quality materials such as steel/aluminum alloys ensuring durability.
  • Barrel twist rate: Ensure that your chosen barrel has an appropriate twist rate (at least one full rotation within about ten inches) to accommodate the weight of rounds you'll be firing continually.
  • Muzzle device type: Different muzzle devices – brakes, flash hiders' compensators – provide varying levels of recoil reduction and noise suppression depending on intended use so choose accordingly!


In conclusion, upgrading your rifle with an AR-15 40 S&W complete upper can significantly improve its performance capabilities by enhancing stopping power and accuracy while also providing greater ammo versatility at reasonable costs per round. When choosing a kit, opt for high-quality components that will deliver reliability and durability in the long run. With these tips in mind, you'll be able to take your rifle to new heights of performance!


What is an AR-15 40 S&W complete upper?

An AR-15 40 S&W complete upper is a firearm part that can be attached to the lower receiver of an AR-15 rifle. It includes all the necessary components, such as the barrel, bolt carrier group, and charging handle, to convert a standard AR-15 rifle chambered in .223/5.56mm caliber into one that fires .40 Smith & Wesson (S&W) ammunition.

The main advantage of using an AR-15 40 S&W complete upper is increased stopping power and improved accuracy at longer ranges compared to handguns chambered in .40 S&W. This makes it ideal for self-defense purposes or hunting medium-sized game.

It's worth noting that installing a new caliber on your current gun requires specific knowledge and skills. Ensure you understand how firearms work before purchasing this product.

Are there any legal considerations when buying or owning an AR-15 40 S&W complete upper?

In most states within US territory there are no specific laws regarding ownership of uppers for rifles like the ArmaLite Rifle Model 4 (AR4) – commonly known as "AR"-style rifles). Nonetheless some states have restrictions concerning possession of certain parts or modifications made on firearms already owned by civilians; it's important you verify them first before making any purchase if unsure.

Can I use my current lower receiver with an AR-15 40 S&W complete upper?

Yes! The great thing about using these uppers is their modularity: they're designed so they fit perfectly onto existing lower receivers without modifications needed beyond disassembling/reassembling them from their corresponding pins.

However make sure you double-check compatibility between both pieces since not all types match together properly -though usually those labeled 'mil-spec' tend to work more often than non-mil-specs ones.

Are there any maintenance tips I should know when using an AR-15 40 S&W complete upper?

Proper maintenance of your firearm is critical to ensure its long-term performance and reliability. Here are some tips:

  • After every shooting session, clean the barrel with a bore brush and cleaning solvent to remove any fouling or debris that may have accumulated during use.
  • Inspect the bolt carrier group for wear or damage, paying special attention to the firing pin and extractor components.
  • Lubricate all moving parts with gun oil or grease as recommended by the manufacturer.

What other accessories do I need to purchase along with an AR-15 40 S&W complete upper?

In addition to purchasing a lower receiver assembly if you don't already own one (since it's needed in order for this product will work), there are several other accessories you might want consider acquiring:

  1. Magazine: A magazine specifically designed for .40 S&W ammunition is crucial since standard magazines meant for .223/5.56mm rounds will not fit properly, leading cycling problems that can compromise reliability.

  2. Optics: Adding optics like scopes can help increase accuracy at longer ranges by providing magnification over iron sights' capabilities.

  3. Muzzle Device: Replacing muzzle devices like flash hiders or compensators can reduce recoil felt while firing – a particularly important feature given higher-powered ammo than compared against "standard" ArmaLite Rifle Model 4 calibers-.

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