Sound Mitigation Buffer SMB H2 (4.7 oz Equivalent)

If you want a smoother recoil cycle and less buffer spring noise, the SMB H2 is a simple upgrade—one captured assembly replaces a standard buffer and spring, so you get a cleaner feel without complicating your build.

Why choose the H2 weight

The H2 class is a popular “middle-heavy” option. It’s a solid choice when a standard carbine setup feels a bit too light, but you don’t want to jump straight to the heaviest buffers.

What it does

• Guides the spring to reduce contact inside the buffer tube for a smoother, quieter cycle
• Helps refine recoil feel compared with many basic buffer and spring setups
• Keeps things straightforward with a single-stage captured design

Specs

• Variant: H2 (4.7 oz equivalent)
• Assembly weight: 5.81 oz (complete system)
• Platform: AR-15
• MPN/SKU: ARM258-H2
• Made in USA
• Warranty: Lifetime

What’s included

• Polymer base guide rod
• Spring
• Buffer

Optional spring tuning

Most users install and run it as-is. If you’re tuning for a specific setup, the main spring can be trimmed to reduce tension in small steps (follow the manufacturer guidance and stay within the published limit).

Notes on fitment

AR-15 recoil setups are usually straightforward, but some builds use non-standard receiver extensions or proprietary parts. If your rifle isn’t a typical carbine-style configuration, verify compatibility before ordering or ask a qualified armorer.

FAQ

What does “4.7 oz equivalent” mean?

It’s the buffer weight class this model is designed to match from a tuning standpoint. The complete assembled unit has its own listed total weight.

Is this compatible with AR-15 builds?

This model is intended for AR-15 platforms. If you’re using non-standard recoil components, confirm fitment before purchase.

What comes in the package?

A polymer base guide rod, spring, and buffer.

Does it help reduce buffer spring “twang”?

That’s one of the goals of a captured system: guiding the spring to reduce contact with the inside of the tube for smoother, quieter cycling.

Can I adjust it?

Yes, spring tension can be reduced by trimming the main spring in small steps, within the manufacturer’s published limit.

How do I choose between H2 and other weights?

H2 is a balanced option. If your setup prefers a lighter feel, choose the carbine-weight version; if you want more mass for a slower cycle, consider heavier variants like H3.