8 Best BCG For 300 Blackout Suppressed

Planning to build a suppressed 300 blackout AR15? Explore the some of the best BCG for suppressed 300 blackout setups. The ideal BCG for this purpose seamlessly integrates with components tailored for subsonic 300 Blackout suppression.

Key considerations include buffer weight, ammunition type, gas system, barrel length, muzzle attachments, and gas pressure dwell duration. The aim is to regulate gas flow, ensuring minimal bolt carrier group over-gassing and reducing gas blowback to the shooter.

While there's a vast product selection, remember that pricier BCGs might offer limited additional value."

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Selecting The BCG For 300 Blackout Suppressed 

BCGs wear out because of the heat, friction, and pressure they face every time you fire your AR-15. By cleaning and taking care of your BCG, and choosing quality parts, you can stop most problems with your rifle and keep your BCG from wearing out too fast.

While most BCG on the market are MPI tested and the gas key is staked, but how can you differentiate among them?

A quality BCG with Parkerized or Phosphate coating will outperform a low-cost BCG that's priced higher due to a coating. This extra coating doesn't provide many benefits over standard options and may lead to more problems.

Adjustable Gas

An adjustable gas BCG is tailored for 300 blackout AR15 rifles with fixed gas blocks using direct impingement. Even when the BCG remains inside the rifle, a tool can easily adjust it. This adjustment minimizes gas blowback, curtails wear and tear, and diminishes BCG overspeed during suppressed firing.

For those with a fixed gas block, an adjustable gas BCG is advisable. However, if your rifle has an adjustable gas block, the adjustable gas BCG becomes less essential.

A standout feature of the adjustable gas BCG is its easy accessibility. Users can tweak it directly via the ejection port. In contrast, an adjustable gas block might be concealed under a full-length rail system, making adjustments more challenging.


The bolt should have a durable and smooth finish like NP3, Chrome, DLC, or Nitride. This finish aids the bolt's lock and release mechanisms. Construct the bolt from C158 steel; however, 9310 steel from top-tier manufacturers with strict quality standards is acceptable.

The ejector must feature a slanted edge and be crafted from S7 tool steel. Using Sprinco ejector springs is advised.

For the extractor, use either 4340 or S7 tool steel and apply a phosphate coating for enhanced case grip. While optional, polishing the extractor's leading edge can be beneficial.

Think about opting for Sprinco 5 coil extractor springs. For barrels shorter than 14.5, utilize both the insert and rubber O-ring from the Sprinco set. For barrels longer than 14.5, typically just the insert is needed.

Bolt Carrier 

For the carriers, 8620 steel is the standard. A chrome-lined bore is ideal, but not possible with Nitride coatings. If money is not an issue, go for an NP3 or chrome coating. If you're on a budget, the standard phosphate coating is effective. Full mass, M16 profile carriers are suggested for duty or defense guns.

Firing Pin, Cam Pin, and Gas Rings Choose a firing pin made of 8640 steel with chrome plating.

The cam pin should be made from 4340 steel and coated with Chrome, NP3, DLC, or Nitride to extend its life. Some companies offer dimpled cam pins for consistent wear and longer life.

BCG For 300 Blackout Suppressed

Bootleg Adjustable BCG

bootleg 300 blackout suppressed bcg

The Bootleg Adjustable BCG is a high-quality bulk carrier group suitable for those looking for adjustability, especially when running suppressed 300 blackout. While primarily advertised for 5.56 caliber or .223, it can be used with the 300 Blackout cartridge, but users should be aware of specific considerations when doing so.

The entire BCG is machined from S7 tool steel grade material with lithium isonite coating to greatly reduce heat damage and corrosion. 

The BCG features a bleed-off style system with 4 adjustable positions, allowing for fine-tuning based on ammunition type (subsonic or supersonic). 

A significant advantage of this BCG is that it eliminates the need for an adjustable gas block, making it an ideal choice for those who prefer a hassle-free setup. Some users expressed a desire for varied finishes, such as nickel boron, but overall, its performance remains commendable.

The BCG has proven effective in reducing gas blowback, especially when paired with suppressors like the Dead Air Nomad. This reduction in gas has led to cleaner internals and an overall improved shooting experience. 

  • Weight: 1 lbs

BCM Bolt Carrier Group

For those using an adjustable gas block and seeking a dependable bolt carrier group for a suppressed 300 Blackout AR15, consider the BCM. While it's a straightforward choice, it offers enhancements over the standard "Mil-Spec" bolt carrier group. Key features of this BCG include a C158 bolt, 4340 extractors, and an ejector made of S7 tool steel.

Additionally, the gas key is forged from 4130 steel, boasts a chrome lining, and is equipped with superior Sprinco extractor springs. It also comes with a sealed gas key and correctly anchored gas key screws. The carrier, made of 8620 steel, is treated with a phosphate coating and has a chrome-lined interior.

  • Bolt: C158 material
  • Extractor/Ejector: Tool steel
  • Gas Key: Chrome-lined and properly staked
  • Carrier: Phosphate with chrome-lined bore

Sons Of Liberty Gunworks BCG

SOLGWs has been making some headline news in the firearm world for making some very rock solid AR15s and the company puts a lot of attention on tight fitting parts.

This BCG is another great option along side BCM.

  • Bolt: C158 material
  • Extractors: 4340 material
  • Ejector: S7 tool steel
  • Gas Key: 4130 steel, chrome-lined
  • Carrier: 8620 steel, phosphate finish with chrome-lined bore

2A Armament AR15 Regulated Bolt Carrier Group

300 blackout bolt carrier group

The 2A Armament BCG is meticulously made for optimized performance by eliminating excess material, ensuring it's lightweight yet efficient.

Constructed from a combination of 7075-T6, 8620, and 9310 heat-treated steel, the BCG ensures prolonged durability. Enhanced with a QPD nitride finish, it excels in resisting wear and corrosion.

A standout feature is its bespoke adjustable titanium gas gate, allowing customization of the gas system for your suppressed 300 Blackout AR-15 

FailZero .300 Blackout BCG

best 300 blackout bcg

The FailZero AR15 BCG stands out for its robustness, reduced friction, hassle-free maintenance, and premium build. It features an EXO Nickel Boron coating, renowned for delivering a seamless cycling experience for a suppressed 300 Blackout with an adjustable gas block. 

This unique coating is prized for its hardness and natural lubricating properties, contributing to the BCG's lasting performance and fluid operation.

AR-15 users appreciate the FailZero bolt, made of MIL-SPEC Carpenter 158 steel, and its extractor that uses a Viton O-ring for added grip. Visually, the FailZero BCG impresses, with many users noting the striking contrast of the Nickel finish against darker rifles.

Given its mid-tier pricing, it's a favored choice for those seeking a high-caliber AR15 BCG for suppressed and none suppressed shooting.

Sionics NP3 BCG

Nickel PTFE, commonly referred to as NP3, offers superior benefits compared to standard coatings. It bolsters lubrication, heightens corrosion resistance, and makes cleaning more straightforward. Distinguishing itself from some budget-friendly Nickel Boron variants, NP3 is notably thin and resists chipping or cracking.

Sionics offers bolt carrier groups showcasing an NP3-coated C158 bolt, paired with a tool steel extractor and ejector. Additionally, the bolt carrier group incorporates a Sprinco extractor spring and Optimized Carrier Key Screws (OCKS) for steadfast gas key anchoring.

  • Bolt: NP3 coated C158
  • Extractor and Ejector: Tool steel
  • Gas Key: Enhanced and secure

BRT Chrome BCG

Forward Controls Design makes this BCG excellent coating protection against corrosion and adds improved lubricity, similar to NP3. Nowadays, Chrome BCGs are less common because they are costly to produce.

However, they remain a great choice for those seeking a coating that's superior to the standard phosphate. BRT's BCG features a Chrome C158 bolt and a full chrome gas key, all secured with properly staked fasteners.

  • Bolt: Chrome C158
  • Gas Key: Full chrome with properly staked fasteners

LMT Enhanced BCG

LMT Enhanced BCG

The LMT Enhanced BCG has a different cam path, extending dwell time to manage suppressed or overly-gassed systems more effectively. Uniquely, it integrates three gas ports, an upgrade from the typical two, optimizing gas circulation. These ports are slanted forward, ensuring surplus gas is deflected away from the user. Additionally, the carrier features distinctive cuts on its bearing areas, enabling smoother movement amidst dirt and obstructions.

The bolt is crafted from an advanced steel type, surpassing the strength of both C158 and 9310. This, combined with a reimagined bolt lug layout, amplifies the bolt's resilience. LMT incorporates a "lobster tail" extractor, employing two springs for increased extraction reliability and a failsafe mechanism. Furthermore, LMT has eliminated the lug opposite the extractor, ensuring a balanced distribution of force among the remaining bolt lugs.

  • Cam Path: Altered to increase dwell time
  • Gas Ports: Three instead of two, for better flow
  • Bolt: Proprietary steel, super strong
  • Extractor: "Lobster tail" design with two springs
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