HUB, Plan B and direct-thread compatibility.
A compatible HUB suppressor can use a HUB-to-Plan-B mount for a Plan B muzzle device or a Direct-Thread HUB Adapter for a confirmed barrel thread. These are different mounting paths, and every component still requires model-specific verification.
What does HUB mean?
In suppressor mounting, HUB commonly refers to a 1.375–24 internal thread at the rear of a compatible suppressor. It allows the suppressor manufacturer or user to select among supported mounting systems. Because products vary, the suppressor manufacturer’s current drawings and instructions are the authoritative source for whether a specific model is HUB compatible.
The Plan B HUB Mount Adapter uses 1.375–24 HUB threads on the suppressor side. Its product specifications also list .900–24 external threads, a 25-degree taper, .700-inch overall length and 1.7-ounce weight.
Suppressor interface
1.375–24 HUB threads must match the suppressor’s supported rear interface.
Plan B interface
The adapter’s mount geometry must match the Plan B compatible muzzle device.
Internal clearance
The assembled muzzle device must not conflict with the suppressor’s internal depth or bore path.
Choose the supported mounting path.
| Mounting path | Suppressor-side component | Firearm-side connection | What to verify |
|---|---|---|---|
| Plan B mount | Plan B HUB Mount Adapter | Compatible Plan B muzzle device | HUB interface, mount geometry, muzzle-device depth and bore clearance |
| 1/2–28 direct thread | 1/2–28 Direct-Thread HUB Adapter | Confirmed 1/2–28 barrel thread | HUB interface, barrel thread, shoulder, bore and suppressor limits |
| 5/8–24 direct thread | 5/8–24 Direct-Thread HUB Adapter | Confirmed 5/8–24 barrel thread | HUB interface, barrel thread, shoulder, bore and suppressor limits |
The complete Plan B mounting path.
| System part | What it must match | What to verify |
|---|---|---|
| Barrel | Plan B muzzle device | Thread pitch, direction, shoulder and caliber |
| Muzzle device | Plan B suppressor mount | Mounting geometry, bore, timing and seating surface |
| HUB adapter | Suppressor rear thread | 1.375–24 interface, supported model and installation limits |
| Assembled suppressor | Entire firearm system | Depth, bore, alignment, caliber, ammunition and barrel restrictions |
Before using a suppressor adapter.
- Check the suppressor’s published rear mounting interface.
- Confirm the adapter is supported for the exact suppressor model.
- Choose either the supported Plan B path or the supported direct-thread path.
- For direct thread, confirm the exact barrel thread and shoulder geometry.
- For Plan B, confirm muzzle-device length, timing and blast-chamber clearance.
- Confirm projectile diameter and bore clearance.
- Follow current torque and installation instructions.
- Verify alignment before firing through the suppressor.
- Stop and consult the manufacturer or a gunsmith if uncertain.
Do not modify parts to force compatibility. Do not rely on brand names, forum posts or visual similarity in place of current dimensions and manufacturer approval.
Frequently asked questions.
Is HUB the same thing as Plan B?
No. HUB describes the rear suppressor interface, commonly 1.375–24. Plan B describes the suppressor mount’s connection to a compatible muzzle device. A HUB-to-Plan-B adapter bridges those interfaces in a supported system.
Is a Direct-Thread HUB Adapter the same as a Plan B HUB Mount Adapter?
No. A Direct-Thread HUB Adapter connects a compatible HUB suppressor directly to a confirmed 1/2–28 or 5/8–24 barrel thread. The Plan B HUB Mount Adapter connects the suppressor to a compatible Plan B muzzle device.
Will either adapter fit every HUB suppressor?
No universal guarantee should be assumed. Verify the exact suppressor model, rear interface, available depth and all manufacturer restrictions.
What Plan B muzzle devices are available?
Plan B offers flash comps and brake comps in 1/2–28 and 5/8–24. Each product page lists its dimensions, weight, timing requirements and caliber information.