INTERCHANGEABLE ENDCAPS
The hole sets what it runs, and how well.
On the Huckleberry, the endcap threads off. It’s the same diffuser endcap as the rest of the line — not a simplified version, not a plate with a hole in it — and what changes when you swap it is the size of the aperture the bullet passes through.
That matters more than it sounds like it should. A larger hole passes everything smaller, safely, and suppresses less while it does. This page is the rule that follows from that, and the marking system that keeps you from getting it wrong in poor light.
Same endcap. One of them comes off.
Every silencer we make ends in a Jet-Turbine Diffuser Endcap™ — the same geometry, formed the same way, doing the same job. Spreading and slowing the gas at the exit instead of concentrating it. Dimpled internal surfaces. Reduced backpressure.
The only difference between the Huckleberry’s endcaps and the ones that don’t come off is that the Huckleberry’s thread off.
That’s worth saying plainly, because it’s the question people ask: do I give something up for the versatility? On the endcap itself, no. It isn’t a simplified part, a plate with a hole in it, or a compromise made to allow it to be removed. It’s the same diffuser, made the same way — it just has a thread on it. What that shape does is identical either way.
What changes when it comes off isn’t the quality of the endcap. It’s the size of the hole, and that’s the entire point.
What the endcap actually does
It’s the last aperture the bullet passes through, and the last shape the gas touches.
The hole has to be larger than the projectile — with enough clearance that ordinary variation in mounting, alignment and barrel harmonics never closes the gap. That clearance isn’t generous by accident. It’s the margin that keeps a bullet from finding metal.
But clearance costs you. Behind every bullet is a column of gas at pressure, and that gas is looking for the fastest way out. The bullet is plugging most of the exit. The gap around it is the rest. Widen the gap and more gas leaves early, alongside the projectile, instead of staying inside where the silencer can take its energy. The wider the aperture relative to the bullet, the less effective the silencer is on that host.
The loss is gradual rather than sudden, which is worth saying plainly: a .30 host with the .36 endcap fitted isn’t broken and isn’t unsafe. It’s just a little less quiet than it would be with the right cap on.
The set
| ENDCAP | APERTURE SIZED FOR |
|---|---|
| .22 | 0.224 in. class projectiles |
| .30 | 0.308 in. class projectiles |
| .36 / 9mm | 0.355–0.357 in. class projectiles |
Larger apertures pass everything smaller. Smaller apertures pass nothing larger.
And a projectile that will not pass does not stop politely.
The rule, not a list
Each endcap is named for the projectile class it’s sized for, and the rule is the same in every case: use the smallest endcap your host will pass.
A larger aperture will physically clear a smaller bullet — but clearance is not a rating. Geometry can tell you a combination is out. It can never tell you a combination is in.
If you’re unsure whether a particular cartridge belongs on this silencer, ask us before you fire it. We answer, and we’d much rather have the conversation now. Say hello →
The threads and the sealing face
Two surfaces do the work of holding an endcap where it belongs, and both reward keeping clean.
The threads locate the cap and carry the load. Carbon accumulating in a thread doesn’t announce itself — it simply makes the cap harder to remove next time, and eventually makes it come off with more force than you wanted to apply.
The sealing face is the flat surface the cap draws down against. It’s what sets the cap square to the bore. Debris on a sealing face is the most common reason a component sits slightly canted, and a canted endcap moves the aperture off center. It’s the same variable the whole silencer is built to control — a bore formed on one axis rather than stacked out of tolerances.
Brush both, look at both, then fit the cap. It takes a few seconds and it protects the thing you actually care about.
The dots
Every endcap and every HUB Mounted Brake™ carries a small cluster of dots — one, two, or three. The dots are a caliber key.
Match the count. A two-dot brake takes a two-dot endcap. Three takes three.
The marking is deliberately subtle. It exists so a configuration can be verified by looking — no chart, no manual, in poor light, with cold hands, which is precisely when the mistake would otherwise be made.
One limit worth knowing: the dots key caliber, not thread pitch. A brake is available in more than one thread for the same caliber group, so matching dots confirms the endcap and the brake belong together — not that the brake fits your barrel. Thread pitch stays a separate check, and the brake side of that system is worth reading before you fit either one.
It’s a small piece of engineering whose only job is to stop you making a mistake in the dark. That’s most of what good manners are.
Changing one
Cool, unloaded, off the rifle. Unthread the old cap, clean the threads and the sealing face, count the dots on the fitted brake, thread on the endcap carrying the same number, and torque it. Full procedure and torque values are in the owner’s manual.
Then look through it. With the silencer off the firearm and the mount installed as you intend to fire it, sight down the bore against a light background. The path should be clear, concentric, and visibly larger than the projectile you’re about to send through it.
That last step isn’t optional and it isn’t occasional. Because the endcap changes, the aperture changes — so the check is new every single time.
The short version
Same endcap as the rest of the line, with a thread on it. The aperture sets what the silencer will run, and how well. Use the smallest one your host allows, match the dots, and look through the bore before you load.
One silencer that follows you from rimfire to .300 Win Mag is a particular kind of purchase. The rest of what it does is worth the five minutes.