Top 4 Best .300 Blackout Buffer Springs [June 2023]

There is no doubt that the .300 Blackout round is perhaps the best option for urban tactical scenarios as it gives you the performances of a 7.62x39mm round with the standard size AR magazines.

With that, you might be thinking about tuning your AR 300 Blackout rifle. There are plenty of ways for you to tune your rifle, but the best way is to switch up your buffet springs. You can follow the guides on this article in selecting the best .300 Blackout buffer springs.

Buffer SpringsNameEditor’s CommentRatingGet The Best Deal
Aero Precision AR15 Carbine Buffer Kit

Most Recommended Option

1. Tight fit to your firearm
2. Lightweight kit
3. Ships with all the components you need

Geissele Super 42 Braided Wire Buffer & Spring Combo

1. Functions smoothly even with poor quality or dirty ammo
2. More robust
3. Durable

8.5/10SHOP NOW
Brownells – AR-15 Buffer Retainer Springs1. Materials and finish at least equal to OEM parts
2. Perfect option for keeping an emergency spare spring
3. Value for money
8.0/10SHOP NOW
PSA PA10 Carbine Buffer Spring1. Old school round wire spring
2. Specifically for PSA’s PA-10 and PTAC Tac-10
3. Cost-effective
8.0/10Currently unavailable

Why Do You Need to Replace Your 300 Blackout Buffer Spring?

In simple terms, you would want just enough buffer weight and spring tension to lock the bolt back on an empty bag. If the buffer weight is too light, you probably won’t get any recoil reduction, whereas if it is too heavy, your bolt might even fail to lock back.

The standard carbine buffer systems on the market are usually optimized for the 5.56mm NATO round, usually based on the specifications of a standard military M4.

If you’ve chosen to buy or build your rifle to chamber a 300 Blackout, not only is your caliber non-standard, your rig is highly customized too. Hence, choosing the right weight or buffer spring is going to take some trial and error.

Different Types of Buffer Weights For 300 Blackout 

Your recoil spring must be paired with the right buffer weight for your 300 Blackout rifle. A buffer would usually be made from a combination of steel and tungsten to achieve the necessary weight. Different terms are used to identify different weights.

Carbine weight is identified as the standard 3-ounce buffer used in mil-spec carbines. They work with different varieties of ammunition, which is great for mid-length setups.


The H1 carbine buffer weighs around 3.8 ounces and works best on an over-gassed AR-15.


The H2 carbine buffer weighs around 4.6-4.7 ounces. These buffers are mainly for practical use with the recent rise of AR-15 pistols as they wouldn’t be ideal for mid-length systems.


The H3 carbine buffer weighs around 5-5.4 ounces, which is very often used with the .300 Blackout, but in fact, more suited to the 458 SOCOM round.

1 thing you should know is that rifle-length buffers are completely of a different species, and they have a standard weight of 5 ounces, which are not interchangeable with the carbine systems.

What Makes A Quality 300 Blackout Buffer Spring?

It’s not as simple as matching the right buffer system to your .300 Blackout caliber. Just like other rounds, the .300 Blackout has both sub and supersonic variants in a range of bullet weights and each would work best with different spring tension.

Other factors include the barrel length, gas port size, muzzle device, bolt carrier group weight, etc. Carbine springs usually feature 37 – 39 coils and rifle springs could come with 41 – 43 coils.

Carbine recoil springs must be over 10’ to be serviceable and rifle springs must be over 12’. You will notice that most recoil springs look like a solid and steel round wire.

Top 4 Best 300 Blackout Buffer Springs

1. Brownells – AR-15 Buffer Retainer Springs



  • Materials and finish at least equal to OEM parts
  • Chrome silicon springs indicated by (CS)


As one of the largest firearms retailers in the USA, Brownells has enough market data to know what you need. That is why they have produced many great quality products of their own from mere components to complete firearms, and the Brownells – AR-15 Buffer Retainer Springs is no exception.

Everyone knows that any firearm and/or component with the Brownells name on it would offer you one of the best bang per buck on the market. The Brownells – AR-15 Buffer Retainer Springs is the classically styled springs that you can expect to live up to Brownell’s reputation in providing top-notch products for reasonable prices.

It would be ideal if you could have a few disposable back-up springs around the corner so that whenever you or your friend’s .300 Blackout rifle stops functioning, you always have a plan to remedy it.

In terms of material and construction, these springs are guaranteed to be at least, as good as those of original equipment manufacturer (OEM) springs. If you have a nice arsenal of sporting rifles that aren’t shooting as well as they used to, these springs could bring back life to them.

You will like this product if:

You are looking for a spare spring for emergency purposes. Available on Brownells for only $2.99 per unit, this is as affordable as a buffer spring can get. Seeing that it’s made and manufactured by Brownells themselves, you can rest assured that you will be getting a solid spring with all the top features with a nice and solid construction.

You might not like this product if:

You want something more. For $2.99, you can’t ask for too much besides great built quality and features. If you are looking for a buffer spring with more advanced technical designs, the Brownells – AR-15 Buffer Retainer Springs wouldn’t be your best option.


2. Geissele Super 42 Braided Wire Buffer & Spring Combo



  • For AR-15 models
  • Made in the USA


Geissele is a company that’s based in Pennsylvania who has built a formidable reputation for itself in the modern sporting rifle scene.

As the name – Geisselle suggests, it means immediate respect down at the range, and with the Geissele Super 42 Braided Wire Buffer & Spring Combo that’s designed to enhance the function and reliability of your rifle, you will be getting that respect from your peers.

The Geissele Super 42 Braided Wire Buffer & Spring Combo is a braided spring with 3 separate wires just like the classic German MG42 machine gun, which is pretty cool. The reason behind this design is so that it can dampen harmonics and absorb more energy as each wire flexes independently.

From there, it will allow your .300 Blackout rifle to be more reliable by lowering the chances of spring failure and displacing any excess energy as you shoot. The braided design of the Geissele Super 42 Braided Wire Buffer & Spring Combo also has a reduced tendency to lose its length and strength over time, making it extremely durable.

This buffer spring is a carbine-length spring which is usually used with a supersonic .300 Blackout ammo. This is because as a relatively stronger spring, it will require more energy transfer from supersonic rounds unleash its full potential.

This extra spring strength would also provide additional reliability when your .300 Blackout rifle is exposed to bad ammo or when you haven’t clean your gun in a while. Another great feature about this spring is its reduction in the twangy noise you might get from legacy springs.

You will like this product if:

You are a careless shooter. If you are careless and often expose your 300 Blackout rifle to poor quality, steel cased, or dirty ammo, the Geissele Super 42 Braided Wire Buffer & Spring Combo would be a great option for you due to its added reliability.

You want your gun to be quieter. Because this spring emits less twangy noise than you would find in a regular legacy spring, you will get to enjoy your shooting session more without any noise interferences from your spring,

You might not like this product if:

You use subsonic 300 Blackout rounds. Unfortunately, the Geissele Super 42 Braided Wire Buffer & Spring Combo was designed to pair with supersonic .300 Blackout rounds as it is a relatively stronger spring that requires more energy transfer from the likes of supersonic rounds.


3. Aero Precision AR15 Carbine Buffer Kit



  • Smooth operation with no sticking
  • Lightweight
  • Solid fit
  • Absorbs recoil


The manufacturer – Aero Precision, is a company based out of Tacoma, Washington, that is specialized in precision machining for the modern sporting rifle scene. This buffer kit isn’t just a simple spring, but a full buffer kit.

Inside the kit, it includes a 6-position mil-spec 7075-T6 aluminum buffer tube, a buffer spring, a carbine buffer (3 oz.), and a lock nut. One thing you should note is that it doesn’t include a stock.

The Aero Precision AR15 Carbine Buffer Kit is one of the best options to have if you have an older .300 Blackout rifle sitting around that you’d want to give new life into. With this buffer kit, you can rest assured as these components are specifically designed by Aero Precision and tested to work well together.

Weighing around 9.8 ounces, this buffer kit is also a great companion that you could tag along on your shooting sessions as a back up just in case anything happens. Since it is precision-machined by Aero Precision to fit your everyday AR-15 solidly, you won’t have any compatibility issues with this buffer spring kit.

In most scenarios, you would be able to fit the spring into your .300 Blackout rifle without any snugs and lateral movement thanks to Aero Precision’s precision machining technologies. Despite being made in the USA, you can still get it at an affordable price, which makes it a great value for money.

You will like this product if:

You are shopping on a budget. The Aero Precision AR15 Carbine Buffer Kit isn’t just affordable, it is a full buffer system that you can rely on to bring life to any old .300 Blackout rifle. Since it’s a kit with all the tools you need, you won’t have to worry when your gun breaks down on the range.

You might not like this product if:

You are a rough user. Unfortunately, with all the great products, even they have their own shortcomings. For the Aero Precision AR15 Carbine Buffer Kit, it’s the packaging. Some complained about the poor protection by the packaging to the buffer tube finish which some rough users might unintentionally cause damage to.


4. PSA PA10 Carbine


  • Old school round wire spring
  • Cost-effective
  • Engineered specifically for PSA’s PA-10 and PTAC Tac-10 lower receivers


If you didn’t know, Palmetto State Armory (PSA) is a veteran-owned, renowned manufacturer of firearms and firearm components based out of South Carolina. PSA is also one of the largest firearms and firearm component distributors in the USA.

Because of that, PSA has all the data and feedback they need to pinpoint what you need. In this case, it’s the PSA PA10 Carbine Buffer Spring.

The PSA PA10 Carbine Buffer Spring is a classic round wire buffer spring that’s applicable in carbine buffer systems. Although it was designed specifically for the use of PSA’s own PA-10 and PTAC Tac-10 lower receivers, it could be used with almost any carbine-sized buffer system so you won’t have to worry about compatibility issues.

However said, the PSA PA10 Carbine Buffer Spring is still optimized to be used along with .308 caliber AR-10 style platforms. As such, it will still essentially work better with supersonic, rather than subsonic 300 Blackout rounds.

In terms of length, the total length of this buffer spring is 11.5’ long and it comes with 31 coils. Overall, the PSA PA10 Carbine Buffer Spring is still a great, affordable option for AR-10 and AR-15 .300 Blackout rifles.

You will like this product if:

You have a tighter budget. The PSA PA10 Carbine Buffer Spring is essentially one of the best cost-effective 300 Blackout buffer springs on the market. The fact that it was manufactured by PSA is an indicator that you’ll be getting a top-quality buffer spring.

You might not like this product if:

You shoot with subsonic 300 Blackout rounds. As mentioned above, because it was optimized to use with .308 caliber AR-10 style platforms, it will only unleash its full potential with supersonic 300 Blackout rounds.

Frequently Asked Questions

Q: What does a heavier buffer do?

A heavier H2 buffer takes longer to move (because it’s heavier), hence it will slow down quicker and minimizes the ‘punch’ of the recoil while still ensuring that the rifle maintains its function.

Q: Can you use a rifle buffer in a carbine?

You cannot use a carbine buffer and/or spring on a rifler’s receiver extension. A rifle-length buffer requires a rifle length buffer tube.

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