While shorter barrels like the 11.5" might have a reduced muzzle velocity compared to longer barrels, they can still be very accurate. While 11.5" barrels are excellent for close-quarters combat due to their maneuverability.
If your existing AR15 short barrel rifle needs an upgrade, here are 7 best 11.5 upper receiver sets you can buy right now. Be sure to check your local gun law and overall gun length to be compliant.
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Best 11.5 Upper Upgrades
PSA 11.5"
This is the most affordable 11.5" AR15 upper you can buy right now from PSA. The upper receiver is all very standard, and the barrel is made 1:7 twist rate with chrome moly vanadium material. It's a carbine length gas system and every other part is mil-spec standard.
What makes this one stand out is its price because PSA makes them inhouse and cut out all the middle man in between, in order to give you this price range way under $350. Check it out
Sons Of Liberty M4-89 11.5"
The Sons Of Liberty Gun Works M4-89 AR-15 5.56 NATO Barreled Upper Receiver is a top-quality gun part. The best part is the sturdy carbine-length gas system and the robust M89 handguard mounting system to keep the entire upper beefy and tight. Users can easily customize it with M-LOK points. You can add your favorite bolt carrier group and charging handle because it doesn't come with them.
The upper is made of strong 7075-T6 aluminum and has an 11.5" barrel made of tough chrome-moly vanadium steel. This barrel has a QPQ finish to protect it from rust.
It works with any mil-spec lower receiver and has been tested for pressure and inspected with magnets. When you add your chosen sights and extras, the M4-89 from Sons Of Liberty Gun Works will be a dependable and powerful gun.
BCM 11.5" Standard
The BCM barrel is top-notch. When you compare it to other barrels, BCM's quality stands out. I highly recommend it. The BCM® MK2 Standard 11.5" Carbine Upper Receiver comes with a MCMR-10 Handguard. It has a 3" Picatinny Rail Section and a BCM MCMR Sling Mount. Bravo Company MFG, Inc., a famous company, made it. They made sure it fits Mil-Spec standards for professionals.
The barrel uses strong Mil-Spec steel. This means it's built to last and work well even in tough situations. It has a chrome-lined bore and chamber, so it needs less cleaning. A special finish protects the barrel from weather and damage. It's made for 5.56 NATO bullets, so it works with many kinds of ammo. The twist rate of the barrel is just right, making it good for different ammo types.
Geissele Super Duty 11.5" Upper
Geissele Automatics presents the Super Duty Upper, packed with the newest weapon tech. This 11.5" upper uses 5.56mm ammo and has a special Sparkout Flash Hider, and a tight fitting connector notch between the upper and the handguard.
The package comes with a 10.5" Super Modular Rail MK16. This rail is like the 13.5" SMR MK16, loved by USASOC operators for how it feels and works.
There's also the Geissele Reliability Enhanced Bolt Carrier Group. It has a special coating to fight rust and wear. The gas key is chrome-lined, and the Cam Pin uses a strong medical steel. This Bolt Carrier Group is stable and feeds reliably.
The package includes the Geissele Stressproof Bolt. It's made from a special Carpenter 158+ steel, making it strong and long-lasting. This bolt is better than regular ones and is coated for extra protection.
Together, these features make the Super Duty Upper from Geissele Automatics a top choice for AR-15 users
Sig Saucer MCX 11.5" Upper
The Sig Sauer MCX 11.5" upper is not easy to find, and it works with a MCX compatible AR15 lower, and essentially convert your AR15 to the Sig Virtus.
This unique factory kit comes with an 11.5-inch barrel that has a special gas system and a design that makes it work smoother and last longer. The barrel has threads and a device to reduce muzzle flash. There's a metal handguard with M-LOK slots and a spot to adjust the gas.
The kit also has parts to connect regular buffer tubes and stocks. You can shoot with the stock folded because of its special recoil system. It also has the SIG Matchlite Duo Trigger for a smooth pull and clear break.
Note: The kit's trigger is best. Using a regular AR-15 trigger might cause problems.
Daniel Defense DDM4 V7 S
The Daniel Defense DDM4 V7 Slim upper looks like the popular MK18 upper. It has a 11.5 inch barrel made of strong chrome moly vanadium steel and uses 5.56 NATO bullets. It also has a 10-inch MFR rail system.
The gas system is the most important part of an AR-15. This upper has a special gas block made of tough 4140 steel. It's coated to protect against rust and damage.
This upper uses a carbine-length gas system. This makes sure the bullets cycle smoothly and eject without problems. The direct impingement system helps with better control and aim.
The 11.5-inch barrel is made of a special steel. It's shaped using a cold hammer forging method, making it strong and long-lasting. The barrel has a 1:7 twist rate, which is great for many bullet weights and helps with accurate shooting.
Bear Creek Arsenal BC 15 11.5" M LOK
The Bear Creek Arsenal BC 15 pistol upper features the 11.5" barrel with a parkerized finish. It has a 1:7 twist and uses a carbine gas system. There's also a 9.5" MLOK rail, a flat-top M4 receiver, a BCA bolt group, a flash hider, and a back charging handle. You can use this 5.56 upper with any standard AR-15 lower.