Microbest Mil-Spec C158 HPT/MPI 5.56 Bolt Carrier Group - Phosphate/Chrome-Lined
In stock
The Microbest BCG has been designed from the ground up with the most avid shooters in mind, using only the best materials available on the market today.  The bolt assembly is machined from Carpenter No. 158® steel, shot-peened, MP marked, HP tested, and has a tool steel extractor that is machined from bar stock.
Features:
- 4340 Extractor spring, mil-spec insert and extractor retainer pin in mag phosphate
- Mag phosphate ejector
- Mil-spec stainless gas rings
- 8620 carrier in FA profile chrome lined
- 4130 gas key with grade 8 retainers and sealed
- 4340 cam pin in mag phosphate
- 8740 firing pin in hard chrome
- 1038 retaining pin in mag phosphate
| Weight | 15 oz |
|---|---|
| Bolt Material | Carpenter 158 Steel |
| Cartridge Compatibility | .223/5.56 NATO/.300 BLK |
| Finish | Mag Phosphate |
| Carrier Profile | M16 |
| High Pressure Tested | Individually HP Tested |
| Magnetic Particle Inspected | Magnetic Partical Inspected |
| Platform | AR-15 |
| Bolt Finish | Mag Phosphate |
| UPC | 14699 |
Compliance
NFA (National Firearms Act) compliance is crucial for legal ownership and transfer of regulated firearms and accessories like short-barreled rifles, suppressors, and certain types of ammunition, ensuring adherence to federal regulations to avoid legal penalties and ensure responsible firearm ownership.
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US
Microbest Mil Spec C158 HPT/MPI Phosphate-Chrome Lined BCG
I bought this BCG for use in a build that I'm planning. Without gauging the components, it appears to be an efficiently gassed BCG, but will confirm with gauging. Microbest makes a very good BCG, so I'm expecting a good result. Great communication and customer service from AR15 DISCOUNT throughout the entire purchase and shipping experience.
USVery good quality bolt carrier group
I am very happy with this BCG. I replaced a BCG that was not chrome lined. This BCG installed without any issues and the rifle functioned flawlessly.
USGTG....
Good deal, (AND reasonable shipping!)l on one of the highest quality BCG's you can buy.
USThe Heart of the AR15 Rifle!
This is an excellent BCG. It's just what I needed for a Retro A1 build, it has the correct mil-spec 8620 carrier steel, the bolt is158 carpenter steel, both the carrier and gas key are chrome lined, and the gas key is properly staked. As an added plus, I purchased this during AR15 Discounts Black Friday sale for $120 and change, including tax and shipping fees. I just recently discovered AR15 Discounts online outlet and since have made several purchases. Their prices are very competitive, shipping is fast with updates provided on the delivery status. Thanks, AR15 Discounts, I've found my go-to online retailer!
United StatesThis is the one....
The BCG is possibly the most important thing in the rifle and this one is perfect. Chrome lined on the carrier and the gas port to tight tolerances ensure long life on the important wear surfaces. The phosphate coating has an ever so slightly rough surface that holds gun oil after hundreds of rounds. I have 3 of these in my ARs and just make sure to oil them before I go shooting. They are flawless.
