Comstock HUB Extended Plan-B Suppressor Adapter

Description

Comstock HUB Extended Plan-B Suppressor Adapter

The Comstock HUB suppressor adapter closes exactly the gap a longer muzzle device leaves at a suppressor’s first baffle. Machined to the Extended/XL (HPA) profile, it adds 0.4″ of blast-chamber clearance over the standard LPA and 0.7″ of overall length, since three-prong and multi-port devices often need that extra room to clear the first baffle cleanly.

Because the rear cylindrical section holds to 1.08″ in diameter, it tucks under nearly all handguards rather than forcing a rail swap. Both the titanium and steel versions of the Comstock HUB suppressor adapter thread onto the same 1.375-24 HUB/Bravo pattern used by Comstock, Rearden, and most other Plan-B-compatible muzzle devices, so the choice between them comes down to weight and budget rather than fit.

Key Features — Comstock HUB Suppressor Adapter

Beyond the shared thread pattern and install hardware, the two builds differ mainly in material and weight, as detailed below.

• Available in two builds: Grade 5 titanium (1.1 oz) with a PVD finish, or 17-4 PH stainless steel (1.9 oz) finished in black nitride
• Standard 1.375-24 threads (also called HUB or Bravo) accept most rifle suppressors
• 1-7/16″ wrench flats and 1.5″ spanner notches allow correct-torque installation and removal
• Adds 0.7″ of overall length and 0.4″ of extra blast-chamber clearance over the standard LPA
• Compatible with Comstock, Rearden, and other Plan-B muzzle devices, including non-Comstock options built to the same standard

 

Why This Product Stands Out

Choosing between the two builds comes down to weight versus budget: the titanium version claims the title of lightest extended titanium Plan-B HUB adapter on the market at 1.1 ounces, while the steel version holds the same distinction among steel HUB adapters at 1.9 ounces. Both come from Comstock Armory, whose manufacturing tolerances show up in how cleanly the wrench flats and spanner notches seat during install.

That said, the choice isn’t just cosmetic. Titanium shaves nearly half the weight, which matters most on lightweight or precision builds where every gram at the muzzle affects balance. The steel version, on the other hand, costs less up front and holds up just as well under repeated suppressor swaps, given that 17-4 PH stainless steel paired with a black nitride finish was chosen specifically for wear resistance at a mount point that gets torqued and de-torqued often.

Either way, the adapter solves the same real problem: a muzzle device too long for a suppressor’s first baffle clearance. Once it’s threadlocked and torqued to spec, it becomes a permanent, low-maintenance part of the build rather than something to think about again.

Ideal Use Cases

Since fit is identical between builds, the deciding factor comes down to how each one gets used:

• Builds running longer three-prong or multi-port muzzle devices that crowd a suppressor’s first baffle
• Shooters standardizing hardware across multiple rifles on the Plan-B/HUB mounting system
• Precision or lightweight rifles where the titanium build’s weight savings matter most
• Budget-focused builds where the steel build delivers the same fit for less

 

Technical Specifications

 

Compatibility Information

Muzzle Device Compatibility: The 1.375-24 HUB/Bravo thread accommodates Comstock and Rearden Plan-B muzzle devices, along with any other muzzle device machined to the same Plan-B standard, because the thread spec — not the brand — determines fit.

Suppressor Compatibility: Any suppressor built around a 1.375-24 HUB/Bravo mounting system accepts this adapter, whether it’s a Comstock, Rearden, or third-party HUB-compatible mount. That said, Comstock Armory notes that some suppressor manufacturers don’t warranty their products when used with aftermarket mounts, so it’s worth checking bullet stabilization and using an alignment rod before finalizing the build.

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Manufacturer: Comstock Armory | Model: HUB Extended Plan-B Adapter (HPA) — Titanium | Type: Suppressor Mount Adapter | UPC: 850069580360 | SKU: HPA-B-TI

Manufacturer: Comstock Armory | Model: HUB Extended Plan-B Adapter (HPA) — Steel | Type: Suppressor Mount Adapter | UPC: 850069580353 | SKU: HPA-B-SS