Young Manufacturing Variable Mass Bolt Carrier Group

Luke C.
by Luke C.

There are a ton of ways that people have attempted to tackle the issue of having a properly tuned AR-15 rifle. The Young Manufacturing Variable Mass M16 Bolt Carrier Group is one new solution in addition to things like adjustable gas blocks, that can help the user get their rifle quickly tuned to work with different types of ammunition, suppressors, and even different cartridges and subsonic loads. The new Variable Mass BCG will come in two different variants with one featuring a chrome finish for better durability and lubricity.

More AR-15 Stuff @ TFB:

The Young Manufacturing Variable Mass Bolt Carrier Group

Variable Mass Carrier includes 4 weights that can be installed at the rear of the carrier

Standard Chrome M16 weight = 11.328oz
Variable Mass Carrier Weight = 10.912oz
Weight 1 0.722 11.552oz total
Weight 2 0.738 11.808oz total
Weight 3 0.780 12.48oz total
Weight 4 0.832 13.312oz total

Perfect for tuning your system for use with suppressors and hotter or lighter loads. Weights are retained with a roll pin in the carrier. BCG disassembly is unaffected by the weight.

Semi-Auto/ Full Auto M16 Complete bolt carrier group made by Young Manufacturing Inc. using MILSPEC quality steel on our in-house CNC machines. All carriers are then heat-treated, hard-chromed and each carrier is chrome-lined in the bolt throat.

– No Forward Assist Serrations. This can work in an upper with forward assist, but the forward assist will do nothing. Perfect for your slick side upper build.

– Standard MIL-SPEC carrier with additional care taken during machining process

– Sharp edges and rough finishes eliminated. Will NOT shred fingers and operates smoothly

– Made of same steel and using same processes as our National Match but to standard MILSPEC design

– The HMB Bolt by HM Defense eliminates the pass through cam pin hole and replaces it with a cam pin socket and radiused cam pin design. The new patented design eliminates the natural weak point of Mil-Spec bolts by significantly increasing the amount of metal (and strength) at the cam pin location. The result- NO MORE BROKEN BOLTS! The HMB Bolt also reduces contact between cam pin and firing pin, enabling smoother operation of firing pin, bolt lugs and aft gas rings. The new cam pin socket also retains lubrication for extended operations.

– Also includes our recoil lug supported gas key

The chrome BCG version of this will cost $349.95 and is a full $70 less expensive than the standard black nitride finish version at $279.95. Some people might take issue with the bolt’s lack of a forward assist, and the omission of this feature might be to reduce machining time and to give customers who have a slab-sided upper an option that more uniformly matches their build. For more information, you can visit the Young Manufacturing website here.

Luke C.
Luke C.

Reloader SCSA Competitor Certified Pilot Currently able to pass himself off as the second cousin twice removed of Joe Flanigan. Instagram:

More by Luke C.

Join the conversation
3 of 13 comments
  • Red dog Red dog on Dec 12, 2023

    Am I reading the price right ? I am getting older. New math I guess.

  • Marcus D. Marcus D. on Dec 13, 2023

    What is the deal with the bolt? Not really clear how it works.

    • W B W B on Dec 15, 2023

      @Marcus D. If you are referring to the HMB bolt: The hole for the cam pin does not go all the way through the bolt, one side is solid so the bolt has much more material and strength than it normally would. High round count (Really high usually) bolts can break at the thin cam pin walls on a normal bolt. It uses a proprietary cam pin as well. Seems like a decent enough idea if you plan on firing thousands of rounds through the same bolt. But most people probably don't need it.