Best Buffer Spring For A 300 Blackout: Dependable Reloading And Accuracy

The entire buffer assembly works together to create the cyclic action of an AR style build. These parts work to reload your weapon and close the bolt to ready for the next shot. It is critical for an uninterrupted shooting experience, and influences your recoil as well. Heavy use of your weapon, rebuilds, or building from the ground up may influence the replacement or introduction of a new buffer, and/or buffer spring to the weapon for a more effective use. 

The 300 Blackout introduces a whole new approach to your weapon, and the huge variance of ammunition you can use in this platform may require you to swap out your buffer assembly parts to find the perfect match. The best buffer spring, and workable buffer, are no true one-size-fits-all solution. There is an excellent selection of quality parts available, and I’m going to explain below what you might want to take into account while making your decision. 

Here’s A Quick Look of Our 5 Best Buffer Springs For A 300 Blackout

Buffer And Buffer Springs Explained

Buffer Springs

A 300 Blackout is so popular because it uses the familiar AR-15 platform to allow a customized shooting experience. It is easy to trade out compatible parts for your shooting style, but may be a bit tedious to find what works best for you due to how many options exist. 

The gas system of your rifle is responsible for firing, ejecting, and chambering the next round, and a quality build is important for efficiency and accuracy. Part of this system is the buffer assembly, made up of the buffer tube, buffer, and buffer spring. Regular use of the spring may begin to wear it down over time, or you may find what you have isn’t giving you the response you need. Either way, you can fairly easily replace the buffer, and/or buffer spring to personalize your use.

When you fire your weapon, the buffer spring recoils and pushes the buffer and bolt carrier forward to load the next round of ammunition, and close the bolt for the next shot. To say it is an important piece is an understatement- but the best part is how incredibly budget friendly it is, as well as easy to add to your build. 

Rifle Length VS Carbine Length Buffers

To understand which springs you need, you first need to understand the differences between rifle and carbine length buffers. These ARE NOT interchangeable, and you will use a rifle length spring with a rifle length buffer and carbine length spring with a carbine length buffer. 

Rifle lengths buffer weights are longer and are used with standard A2 buffer tube often found in a fixed stock design. The added length of the rifle buffer helps fill the void in the A2 rifle buffer tube. A carbine length buffer weight are used with most collapsible stocks that use the shorter carbine length buffer tube. However, choosing your buffer weight is dependent on quite a few factors, such as the gas system used, size of the gas port, ammunition being used, and even if you are using a  suppressor

To keep this nice and simple(ish) we are purely looking at the buffer spring itself, and not the whole assembly. But you still have to match your parts in order to make them work. 

Buffer Springs Re-examined


In your research you may find a lot of information about how this whole system works, but many people the weights and parts are easily confused (and for good reason since they all work together). Word to the wise: don’t confuse the buffer weight with spring weight. Your spring is determined by the buffer, not the other way around. 

When you are determining what spring you need, it is quite simple: you need to choose the spring that works with the existing buffer weight you already have. Unless you plan on rebuilding the entire system, you don’t need to know all the details of it all, expect how they work together. 

Buffer springs are all fairly similar in nature. Rifle and carbine springs have the same diameter, but vary in length to match the buffer. 

  • Standard Carbine Spring – 10.5” with 37 to 39 coils
  • Standard Rifle Spring – 12.75” with 41 to 42 coils

Issues with the spring surround how they rub the internal surface of the buffer tube, creating a ‘twang’ sound and wearing on the tube over time. Generally this is that big of a deal, but has influenced a spring polishing technique to decrease noise and smooth out the action. 

It also has influenced a combination buffer-spring assembly to eliminate friction altogether, however this does cost significantly more than a traditional spring. 

Why You Would Replace A Buffer Spring

Buffer Springs

This small, cheap part is more or less one of the most important components of your weapon. Without it your gun wont’ fire, and so evaluating spring use and efficiency should be a regular part of your maintenance. 

Visual Inspection

One of the best things you can do is remove your spring to give it a good visual inspection. Look for uneven spring wear and/or any pits in the metal in case defects passed inspection that have become noticeable with use. 

Measure The Spring

The consistent compression of the spring will begin to shorten it over time. A good rule of thumb is to measure it when you first purchase it, and check periodically for changes in length. However, as long as a rifle length spring is longer than 12 inches, and a carbine length spring is longer than 10 inches, you should be fine. 

Sound And Feel

If your weapon begins to sound differently during reloading, or you are finding your bullets jam occasionally and you have ruled out other reasons, it might be your spring. Anytime loading is not what you expect, consider what replacing your spring might do for you. 

How To Change Your Buffer Spring

Want to see how easy it is to change your buffer and buffer spring? Take a look at this!

Top 5 Buffer Spring For A 300 Blackout Reviews

The following choices are quality options you can take advantage of for both buffer spring, and buffer and buffer spring combinations. These are tried and true products that are the best bang for your buck, and provide you options to help find the perfect combination for your shooting experience. 

1. Nemo – .300 Blackout Carbine Buffer Spring

  • Length: Carbine
  • Features: Durable stainless steel, made specifically for .300 BLK round use

This is one of the only springs designed specifically for a carbine length 300 Blackout system. It is made for reliable function with subsonic ammunition and can help with short-cycling in under-gassed weapons. Made from a 17-7 stainless steel, this is a durable choice and can work with a large array of other loads, especially those that are being used without suppression. For the price, it is worth the investment to use for improvement qualities. 

Who This Is For

When you run a majority of subsonic rounds, or have issues with short stroking and want a quality replacement, this is absolutely worth considering. 


  • Fixed factory issues incredibly well
  • Amazing choice for a wide range of loads
  • Perfect solution for short stroking 300 BLK issues


  • May not work with all supersonic rounds well

2. Strike Industries – AR-15 Carbine Flat Wire Spring

  • Length: Carbine
  • Features: Flat wire for less buffer wear, lessons vibration

When you want to upgrade your cabine system, this flat wire spring is designed for a smoother shooting experience, and increases the service life of the platform. It also is noted as a highly consistent option, and provides incredible resistance to high cyclic rates. Made from a Cryo-cycled 17-7 ph steel, this lends itself well for strength, increased bolt load, and lessons vibration (including the ‘twang’ sound).

Who This Is For

If you are looking for a dependable, quality spring upgrade for a good variety of AR platform shooting experiences, this is a great choice. 


  • Great for competitive reload time
  • Excellent for over-gassed issues
  • Definitely lessons sound and vibration


  • May be a bit challenging to fully seat

3. Geissele Automatics LLC – Super 42 Braided Wire Spring & Buffer

  • Length: Carbine
  • Features: Three strand wire braid, designed for sound and recoil reduction

The braided wire spring and buffer combination designed by Geissele Automatics is backed by a strong industry brand to provide function and reliability to an AR platform. The braided design dampers both sound and energy as the three threads flex separately from one another. This provides a quieter shooting experience and lessens recoil for high caliber rounds, and is one of the more unique, high-quality combinations you can install. 

Who This Is For

If you want to suppress both sound and recoil, and do so with one of the best buffer combination designs available, this is a great choice. 


  • Smooths out recoil
  • Amazing sound reduction
  • Long-lasting and durable- easy to install


  • Best for supersonic loads, and may be too powerful for subsonic loads 

4. Armaspec Stealth Recoil Spring SRS-Carbine, 3.3oz – ARM153

  • Length: Carbine
  • Features: No metal on metal contact, easy drop in system, reduces sound and recoil

Drop in spring and buffer combinations are an excellent choice to help reduce interior buffer tube wear and tear, and provide a quieter shooting platform. This also reduces recoil for a wholly enjoyable shooting experience. Since the springs never fully compress, it makes an overgassed system work much more effectively as well- and is crazy easy to install. 

Who This Is For

Perfect for recoil reduction, sound reduction, and overgassed systems, this is a perfect option when you want to add a quality drop in buffer and spring system into your AR build. 


  • Noticeably reduces noise and recoil
  • Works great for both subsonic and supersonic loads
  • Consistent cycling and reload times


  • May not be as quiet as some competitors

5. Armaspec Sound Mitigation “H2” Buffer – ARM158-H2

  • Length: Carbine
  • Features: No metal on metal contact, easy drop in system, reduces sound and recoil

When you want the heavier system for your AR shooting platform, and prefer the H2 Buffer tube option, this drop in buffer and spring combo is excellent. Designed for reduction in recoil and sound, and to provide the accurate efficiency for a heavier round, it is easy to install and is a dependable, quality item. It also avoids metal on metal wear for a longer lasting, more accurate 

Who This Is For

When you want the consistent use for a heavier buffer system, this is a great choice. It is easy to install and is perfect for sound and recoil suppression. 


  • Excellent option for subsonic rounds
  • Works great for pistol length 300 BLK platforms
  • Great for subsonic ammunition


  • If jamming occurs you need a lighter system


AR platform builds create a huge array of options, but your choice of buffer springs may sound like a simple task, yet is incredibly important. The thing to keep in mind is that without an efficient spring, you won’t be firing much at all, so pay close attention to your gas length system in general and what size buffer tube assembly you are using. If something isn’t right, you may want to trade out springs or spring and buffer combinations to determine which is best for you!

The options we’ve provided above allow for some specific 300 BLK builds, as well as some products that can work across a variety of platforms, If you are unsure of which direction to go, stay simple and play with various springs depending on the type of round you prefer to shoot. Also, never hesitate to ask manufacturers their opinion concerning your specific build combinations. You will almost always get excellent advice on what to consider.