Armaspec have recently released the third generation of their Sound Mitigation Buffer or SMB. This AR-15/AR-10 buffer assembly has a captured recoil spring that does not contact the internal surface of the buffer tube thus resulting in smoother and quieter operation of the action. Let’s take a closer look.

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Armaspec SMB Gen3, H3

Armaspec Sound Mitigation Buffer Gen3 is a drop-in part that simply replaces the standard AR-15/AR-10 recoil spring and buffer without any modifications to the weapon. The spring weight can be adjusted by cutting the spring with about .25 lbs per coil of tension reduction. The company does not recommend trimming more than 12 coils off the spring. The Sound Mitigation Buffer for AR-10 rifles has an overall weight of 7.2 oz which is the equivalent of using a 4.7 oz buffer. The SMB Gen3 for AR-15 rifles is available in five different weight configurations. The list of weight options and their standard AR-15 buffer equivalents can be found below.

• Actual Weight (Complete System):
  • Carbine: 4.41 oz
  • Heavy: 4.91 oz
  • H2: 5.81 oz
  • H3: 6.71 oz
  • 9MM: 9.88 oz
• Equivalent Weight:
  • Carbine: 3.3 oz
  • Heavy: 3.8 oz
  • H2: 4.7 oz
  • H3: 5.6 oz
  • 9MM: 6.9 oz

AR-15 SMB Gen3 options. Left to right: Carbine, Heavy, H2, H3, 9mm.

The 9mm version of SMB Gen3 has a longer polymer end piece limiting the bolt stroke distance as well as a stronger spring. As mentioned by Armaspec, “for proper function of the SMB-9 in your 9mm rifle or pistol, the extra weight on the back of the bolt carrier needs to be removed“.

Armaspec SMB Gen3, 9mm

Both the AR-15 and AR-10 versions of Armaspec Sound Mitigation Buffer Gen3 are listed on the company’s website at an MSRP of $59.99. The choice of buffer weight will not affect the price. Extra Sound Mitigation Buffer weights can be purchased separately for $14.99. The Armaspec SMB Gen3 is made in the USA and comes with a lifetime warranty.

Pictures by Armaspec Inc., www.armaspec.com