What is 308 Bolt Carrier Group? 🚨
It refers to a specific type of bolt carrier group designed for firearms chambered in .308 Winchester or similar cartridges. The BCG is a critical component of a semi-automatic or fully automatic firearm’s operating system. It is responsible for loading, firing, extracting, and ejecting cartridges.
How It Works 🔊
- 🔫 Loading: The BCG starts its cycle by moving forward, stripping a fresh round from the magazine and chambering it into the barrel.
- 🚀 Firing: Once the round is chambered, the BCG locks the bolt into the barrel extension. When the trigger is pulled, the firing pin strikes the primer, igniting the propellant.
- 💥 Unlocking: As the propellant ignites, it generates high-pressure gas that pushes the bullet down the barrel. Simultaneously, some gas is tapped through the gas port in the barrel.
- 🔑 Gas Operation: The gas enters the gas block and travels through a gas tube into the BCG’s gas key. The gas key directs the pressurized gas into the BCG, providing the force to cycle the action.
- 🏋️ Cycling: The pressurized gas pushes the BCG rearward. The carrier, connected to the bolt, moves with force, unlocking the bolt from the barrel extension.
- ♻️ Extraction and Ejection: As the BCG moves rearward, the extractor hooks onto the rim of the spent cartridge case. The BCG continues moving, pulling the spent casing out of the chamber and ejecting it through the ejection port.
- 🏭 Cocking: As the BCG reaches its rearmost position, the firing pin is reset, and the hammer or striker is cocked, preparing for the next shot.
- 🔄 Return to Battery: The recoil spring, located within the BCG, drives the BCG forward, pushing a new round from the magazine into the chamber.
- 🔒 Locking: The bolt rotates and locks into the barrel extension, securely chambering the new round.
- 🔫 Ready to Fire: With the BCG in its forward position and a fresh round chambered, the firearm is ready to fire again by repeating the process from step 2 onward.
Finishes 🔌
Parkerized Finish 🌑: A phosphate coating that provides corrosion resistance and a matte black appearance. |
Nickel Boron Coating 🎇: A durable and lubricious coating that enhances wear resistance, reduces friction and offers a distinctive silver or grey appearance. |
Melonite Finish 🔥: Also known as nitride coating, it improves hardness, corrosion resistance, and reduces friction. It typically results in a black finish. |
DLC Coating 🖤: Diamond-like carbon coating provides excellent hardness, wear resistance, and low friction. It often results in a dark or black appearance. |
Stainless Steel Finish 🌟: Some bolt carrier groups are made of stainless steel, which offers excellent corrosion resistance and a polished or brushed silver appearance. |
Titanium Nitride Coating 🌈: A gold-colored coating that provides enhanced durability, wear resistance, and reduced friction. |
Cerakote Finish 🎨: A polymer-ceramic composite coating that offers a wide range of colors and provides excellent corrosion resistance and durability. |
Chrome Plated Finish ✨: A chrome plating that offers enhanced corrosion resistance, smooth operation, and a reflective appearance. |
Features ✅
- Compatibility with .308 Winchester or similar cartridges 🎯
- Increased size and weight compared to BCGs for smaller calibers ⚖️
- Durable construction using materials like steel or nickel boron coating 🏗️
- Reliable extraction and ejection of spent cartridges ♻️
- The gas key for redirecting gas pressure from the barrel to operate the BCG 🔑
- Enhanced strength and durability to handle higher pressures 💪
- Designed for use in AR-10 or similar platforms 🎯
- Smooth and reliable cycling for improved firearm performance 🔄
- Compatible with semi-automatic or fully automatic firearms 🔫
- Designed to handle increased recoil and bolt speed 🏋️
- High-quality components for longevity and reliable operation ⭐
- Bolt carrier with appropriate weight and dimensions for proper function 🚚
Best 308 Bolt Carrier Group | Best 308 BCG
1# Aero Precision .308 BCG Black Nitride
The first model is a .308/7.72 Bolt Carrier Group that will make customers happy with a reasonable price and solid materials. The BCG is made of 8620 steel with a nitride coat, which makes the construction durable and minimizes the use of lubricants, thanks to the low friction rate. The materials used for other parts, such as a gas key, firing pin, or bolt extractor are 4130, 8740, and 4340 steel correspondingly. The bolt is tested and inspected, and it’s compatible with all .308-based cartridges.
2# JP Enterprises Complete JPBC 308 Bolt Carrier Group
One of the nice models designed by JP Enterprises is made specifically for AR-10. The components are made of stainless steel, which guarantees you a long service life. When used with JPSCS-9MM, the firing impulse is fast, thanks to the reduced stroke length. The bolt bounce is also reduced, which increases accuracy and reliability. A tighter firing pin channel also reduces pin wear. The model looks nice and works great, but costs a little more.
3# Spikes Tactical .308 BCG
For quite the same price, you can buy this bolt carrier group that is made of 8620 steel with either phosphate or nickel boron finish. Based on our experience carrier and gas key have beautiful chrome interiors that can last for many years. The bolt itself is made of 9310 steel. This is a good, reliable model without extra features that will make you poor.
4# Ballistic Advantage .308 Bolt Carrier Group
Let’s increase the price gradually. Here we’ve got an 8620 alloy steel carrier with a 9310 alloy steel bolt. Plus, an S7 tool steel extractor. The outstanding feature of this BCG is the existence of forward-assist serrations. The BCG ensures a smooth shooting experience, and it serves as a great add-on for your rifle.
5# Faxon Firearms .308 Bolt Carrier Complete – Nitride
One more nice model that ensures long-lasting performance and high shooting efficiency. Thanks to the nitride-finished 9310 steel bolt and solid extractor, carrier, and key, fouling, and friction are reduced. The bolt carrier group also features forward assist serrations. This guarantees good precision and proper functioning of your firearm. Besides, the price is rather reasonable, which is always good.
6# CMC Triggers Enhanced AR BCG
This one is especially good for suppressed or short-barreled rifles because it ensures the proper gas pressure, improving extraction. The case-hardened 8620 steel carrier with 3 forward ports and the black nitride finish ensures the smoothest operation. The bolt is also made of 9310 case-hardened steel with a nitride finish, which decreases possible friction. This is a good model for a low price, so you’d better not miss it.
7# Next Level Armament DLC 308 BCG
What concerns this model, it differs a bit from those we have seen earlier. Thanks to the expanded rear, the cycling in the buffer tube is much better. All internal parts are coated, and the bolt is made of SAE 4140ph high-grade steel, which makes the entire construction durable and strong. It has great resistance to structural failure.
8# Guntec Usa Guntec BCG Ar10 .308 Mil-spec Nitride
Just another good example of a bolt carrier group. A standard 9310 hardened steel bolt with an 8620 carrier and properly staked gas key will improve your AR-10 with a breeze. The nitride coat plays a big role in ensuring a smooth shooting experience. This brand is very reputable on the market, so you will not get disappointed.
9# LANTAC M-SPEC BCG
This is, perhaps, one of the cheapest models. However, it still offers decent characteristics, which is hard to find nowadays. This is an 8620-steel heat-treated and hard ground carrier that suits MILSPEC. Using this product, our team found that the materials for the bolt are a bit less solid but still very reliable, and it’s Carpenter 158. The bolt is also hard ground and it’s shot-peened. Altogether with the nitride finish, the BCG works perfectly.
10# CMMG, Inc .308 BCG
Although this model is worth buying, it has some peculiarities that are needed to be mentioned. First of all, this a semi-auto bolt carrier group, which means it suits only CMMG Mk3. The phosphate finish makes it more durable and efficient. We would say that it’s a good choice if you have nothing else.
11# Alpha Shooting Sports Premium Nitride 308 BCG
If you are looking for a cheap yet well-designed solution, this BCG is a must-have for you. Nothing is outstanding, it’s just a good model for a low price. A solid 9310 steel bolt and an 8620-steel carrier are coated with premium nitride, which reduces pollution and friction. In addition to this, the construction has forward assist serrations, which is also a great advantage that ensures proper functioning.
12# Black Rain Ordnance Bolt And Carrier Group Nickel Boron .308
What is curious regarding this model, is that you won’t find a lot of information about it. But it’s one of the priciest models. The reason is that it uses solid materials and a nickel-boron finish, which is not cheap. Different reviews would say it’s a good model that is a little overpriced.
13# Wilson Combat 308 BCG
Another rather expensive model that requires no presentation. It’s a steel bolt carrier assembly that has a nickel-boron finish just like the previous competitor. With the help of this little add-on, you will make your AR rifle stronger. Get ready to spend some money if you want a good custom weapon.
14# Sharps Rifle Co. XPB 308 Balanced BCG
With a case-hardened 8620 alloy steel carrier and a robust 9310 nickel-chrome-moly alloy steel bolt covered with matte diamond-like carbon, the last model guarantees the best shooting experience for any AR-10 or AR-15 rifle. The gas key is properly staked, the cam pin and extractor are Manganese Phosphate coated, and so on. This is a good buy that costs a rather big sum.
#BONUS: Aero Precision M5 20in .308 Complete Upper Receiver
If you are looking for a BCG, you should also at the upper receiver block that comes with all necessary elements but still offers good customization optionality. This model is a good solution for .308 caliber. It’s forged from 7075 T6 aluminum, which makes it durable and reliable. However, you have to choose the upper receiver first.
Installation 💡
Step 1. Ensure Safety: Before beginning any work, ensure that the firearm is unloaded and the chamber is empty. Follow all firearm safety procedures, such as wearing safety glasses and working in a well-ventilated area.
Step 2. Disassemble the Firearm: If necessary, follow the manufacturer’s instructions to disassemble the firearm until you reach the point where the BCG can be removed. This typically involves removing the upper receiver from the lower receiver and separating the two halves.
Step 3. Remove the Existing BCG: Carefully remove the existing BCG from the upper receiver by pulling it straight out towards the rear of the firearm. Be mindful of any small components like the retaining pin or firing pin retaining pin that may require separate removal.
Step 4. Prepare the New BCG: Ensure that the new 308 BCG is clean, free of debris, and properly lubricated according to the manufacturer’s recommendations. Inspect the BCG for any damage or defects.
Step 5. Insert the New BCG: Align the new BCG with the rails inside the upper receiver and insert it into the receiver. Slide it forward until it is fully seated against the barrel extension. Ensure that the gas key aligns properly with the gas tube.
Step 6. Check Alignment: Verify that the BCG is properly aligned with the barrel extension and that the bolt is fully locked into place. Ensure that the charging handle moves freely and that the BCG operates smoothly.
Step 7. Reassemble the Firearm: Follow the manufacturer’s instructions to reassemble the firearm, attaching the upper receiver to the lower receiver. Ensure that all components are properly aligned and secured according to the manufacturer’s specifications.
Step 8. Function Test: After reassembly, perform a function test by ensuring that the safety selector, trigger, and other controls operate correctly. Cycle the action to confirm that the BCG moves smoothly and that the firearm functions as expected.
FAQ ❓
Conclusion ⏰
The 308 Bolt Carrier Group (BCG) plays a crucial role in the reliable functioning of firearms chambered in .308 Winchester or similar calibers. With its durable construction, compatibility with specific platforms, and ability to handle the higher pressures and recoil associated with this caliber, the 308 Bolt Carrier Group provides reliable performance and improved functionality. While individual experiences may vary, users generally find the 308 BCG to be a reliable and essential component that enhances the overall performance of their firearms.✒️🛒
#Best #308 #BCG #Bolt Carier Group #Sale #For the money #AR 15 #AR #Lightweight #Aero Precision #Reviews #Cheap
My life has taken me through different complications and exciting moments, so what I’ve learned is to always be ready to fight. My father is professional military personnel and he made me familiar with various weapons since my childhood. My first one was a bow, and then I started to have a fancy for this unbelievable world of firearms. My main specialization allows me to share my thoughts about different devices, guns, and gun details with the English-speaking community. In my articles, I talk about pistols, rifles, knives, shotguns, and many other tactical and survival things.
Read more about our team of expert authors.
Affiliate Disclosure: Rotorm.com sometimes gets paid for listings, through sponsors or affiliate programs like Amazon, Optics Planet, Lucky Gunner, Brownells, Cabelas, Rainier Arms, 5.11 Tactical, Bass Pro Shop, etс. Clicking a link helps keep Rotorm.com free, at no extra cost to you!
About the author: Each article on our site is written by experts in survival and tactical equipment, gun enthusiasts, extreme travelers, military, law enforcement and desperate professionals, read about the author at the bottom of the article or visit "About Us" page.
Note: The views and opinions expressed in this article are those of the authors and do not necessarily reflect the official policy or position of any agency.
Hello. Thank you for the information about cleanig. How often should I clean and maintain my 308 BCG?
🟡 Regular cleaning and maintenance are essential for the proper function and longevity of a 308 BCG. The frequency of cleaning depends on factors like usage, environmental conditions, and ammunition type. It is recommended to clean and inspect the BCG after each shooting session and follow the manufacturer’s guidelines.
I recently assembled an AR308 and it seems to be experiencing issues with ejecting. Originally, I had a carbine stock on it and the barrel measured 20 inches. I’ve since replaced the stock with a Luth Rifle stock kit, but the issue of short-stroking persists. I’m wondering if the problem might be with the BCG.
Hello everyone! Are BCG components like firing pins or cam pins interchangeable between different manufacturers?
🟨 Some BCG components may have universal compatibility within the same platform, such as firing pins, cam pins, or retaining pins. However, complete BCG assemblies may not be interchangeable between different manufacturers due to variations in dimensions and specifications.
I am building my first AR10 and need to buy a BCG. I have already purchased an Aero upper and lower. Which BCG do you recommend from the options below?
Please reqad our article ☝️ There are some options
If you purchase a barrel from Faxon simultaneously, they will provide the service of headspacing for you.
I recommend to avoid NiB coating and instead consider Nitrite or DLC coating. Similarly, it is advised to avoid Aero BCG.
We have 2 NB BCG’s from Aero, both have run perfectly 🇺🇸🇺🇸