.22 LR — The Best Host, and What to Do About an Orphan Can

Figure 1 — A rimfire suppressor's operating envelope: trivial gas energy, enormous fouling rate. Source: original diagram.

The .22 Long Rifle is the cartridge suppressors were made for, and it is the one where a suppressor most completely changes the experience. It is also the filthiest thing you can put in front of one. The .22 Rimfire dive covers the ammunition side in depth; this volume is the hardware.

3.1 Why .22 Is the Best Host

Almost no gas. A .22 LR carries on the order of a grain of propellant. The energy a can has to absorb is trivial by centerfire standards, which is why a four-ounce aluminium tube achieves what a rifle needs sixteen ounces of titanium to do.

Figure 2 — A suppressed Ruger 10/22 — the exact architecture two of the rifles in this collection use, though this is not one of Jeff's. Four ounces of can on a 1/2×28 muzzle changes what the rifle is for. So… — Figure 2 — A suppressed Ruger 10/22 — the exact architecture two of the rifles in this collection use, though this is not one of Jeff's. Four ounces of can on a 1/2×28 muzzle changes what the rifle is for. Source: commons.wikimedia.org, CC BY-SA 4.0.

Natively subsonic ammunition is cheap and everywhere. CCI Standard Velocity at 1,070 fps is not a specialty product; it is the ordinary stuff, it costs less than the high-velocity ammunition, and it is subsonic straight out of the box. Every other cartridge in this dive has to buy its subsonic performance with either money or compromise.

Everything is threaded 1/2×28. One thread pitch, one can, an entire battery.

The result is genuinely quiet. Not Hollywood quiet, but the practical benchmark from the rimfire dive: a subsonic 40-grain load through a good can peaks at roughly the same level as manually cycling the action of the gun firing it. Once you reach that, the can has done all it can do, and what you hear is the machine.

3.2 Why It Is the Worst Guest

A .22 LR bullet is bare lead with wax lubricant on the outside. Every shot atomises some of both into a chamber that is never hot enough to burn it off and never pressurised enough to blow it out. Add carbon and primer residue and a rimfire can accumulates fouling at grams per few hundred rounds.

Figure 3 — A rimfire can broken down: tube, end cap, and the baffles laid out in order. Photographing the stack in index order before the first disassembly is the insurance §3.4 asks for. Source: web, referen… — Figure 3 — A rimfire can broken down: tube, end cap, and the baffles laid out in order. Photographing the stack in index order before the first disassembly is the insurance §3.4 asks for. Source: web, reference use.

Two consequences, both absolute:

A rimfire can must be user-serviceable. No exceptions. A sealed rimfire can is a disposable object. (How Suppressors Work Volume 6 covers the mechanism, cleaning methods, and the ammonia-versus-aluminium warning that will otherwise destroy a can.)

Carbon lock is the way rimfire cans die. Left unserviced, the baffles fuse to each other and to the tube and the assembly becomes a solid machined lump. Clean at 300–500 rounds, or before the end cap gets hard to turn.

The one product that meaningfully changes this: CCI Clean-22, whose polymer coating replaces the wax lubricant. CCI claims up to 60% less suppressor lead fouling. For anyone running a rimfire can — and especially for anyone running one they would rather not disassemble more often than necessary — that is the highest-leverage change available, and it is just a different box.

3.3 The Cycling Constraint

The problem specific to semi-auto rimfire: the quietest ammunition has the least momentum, and a blowback action needs momentum to run.

Table 1 — 3.3 The Cycling Constraint

Load	Velocity	Suppressed result	Cycles a 10/22?
CCI Standard Velocity, 40 gr	~1,070 fps	Very good	Yes — the workhorse
CCI Suppressor, 45 gr HP	Subsonic	Better	Generally yes
Federal AE Suppressor, 45 gr	Subsonic	Better	Generally yes
CCI Quiet-22 Semi-Auto, 45 gr	Subsonic	Very good	Engineered to, yes
CCI Quiet-22, 40 gr	~710 fps	Dramatically quieter	No. Single-shot only

If a semi-auto will not run subsonic ammunition, the mechanical answers are a lighter recoil spring (commonly a 10% reduction) or a lighter bolt — with the standing warning that a lighter spring plus high-velocity ammunition batters the action unless a bolt buffer is fitted. Bolt mass is the primary control on cycling in a blowback; spring rate controls bolt velocity.

A bolt-action or single-shot .22 sidesteps all of it and is meaningfully quieter than any semi-auto with the same can and load, because the action noise that dominates a well-suppressed rimfire shot is not there.

3.4 The Can on This Bench: Mack Brothers Lima

The rimfire can in this collection is a Mack Brothers Lima, S/N L1265, on 1/2×28, moving between six .22s: two Ruger 10/22s (a blued DSP and a stainless Takedown), a Ruger Precision Rimfire, a Ruger Mark III, a Ruger Mark IV, and a S&W Model 41.

Its status, checked 2026-07-29. The Lima is not in Mack Brothers’ current catalogue. Their current rimfire model is the VAPOR: 100% titanium, 5 3/8 in, 4.3 oz, a stack of eight K-baffles, an integrated disassembly tool, rated .22 LR / .22 WMR / .17 HMR / 5.7×28.¹

This is the good version of that problem, and the distinction matters. Mack Brothers is still trading, still building rimfire cans, and has a public record of continuing to service and repair discontinued models — they said exactly that when they ceased production of the MB762 and MB556 in 2024.² An orphan product from a living company is a completely different situation from a dead company’s product.

What follows practically:

You are the parts supply. Handle disassembled baffles like irreplaceable objects, because they may be.
Photograph the stack in index order before the next disassembly, not after. Five minutes of insurance against a permanent mistake.
Clean it more often, not less. Carbon lock on a supported can is a repair; on an orphan it is the end of the object. Clean-22 (§3.2) buys real margin here.
Ask Mack Brothers directly what service they will still perform on a Lima, and get the answer in writing before you need it. Do this while the company is trading; the answer is worth more than the can.

3.5 Should It Be Replaced?

Not because it is discontinued. A working rimfire can does not become worse because the catalogue moved on, and there is no performance cliff between a good 2015 rimfire can and a good 2026 one — the physics have not changed and rimfire is where the least engineering headroom exists.

The arguments for adding a second rimfire can are better than the arguments for replacing this one:

Six hosts, one can. Every mount and dismount is a POI change and a wear cycle. A second can means the Model 41 and the Precision Rimfire keep permanent zeroes.
A can in cleaning is a can not shooting. Rimfire cans spend real time disassembled.
The 2026 price floor. Lyman’s Sonicore Skarv 22 landed at $199,³ and the federal transfer tax is now $0. A second rimfire can costs less in 2026 than the tax stamp alone cost in 2024.
Risk management on an orphan. If the Lima ever does become unserviceable, the battery is not disarmed.

3.6 The 2026 Rimfire Field

Reported specifications and positioning. All the usual caveats: retailer-sourced, dB figures not comparable across sources, verify anything that would change a purchase.

Table 2 — 3.6 The 2026 Rimfire Field

Can	Construction	Notes
Dead Air Mask HD	Grade 9 titanium + 17-4 stainless	The consensus “best overall.” Click-together baffles — the best cleaning experience in the class. Full-auto rated, and rated for 5.7×28. Commonly quoted around 39 dB reduction (their protocol)
Rugged Oculus22	100% stainless	Modular full/short. Stainless is heavier but takes any cleaning chemistry and shrugs off abuse. Note it is not titanium despite common assumption
Mack Brothers VAPOR	100% titanium	5 3/8 in, 4.3 oz, 8 K-baffles, integral tool. The in-family successor to the Lima
OCL Titanium 22	Titanium	Lightweight-first
HUXWRX FLOW 22 Ti	Titanium, flow-through	Flow-through applied to rimfire — less blowback into a semi-auto action, which on a dirty .22 is a genuine and underrated benefit
Lyman Sonicore Skarv 22	3D printed	$199. The new price floor, from a mainstream brand, printed

How to read that list. For a shared can that lives on six guns and gets cleaned constantly, cleaning ergonomics outrank the last decibel — which puts the Mask HD’s click-together stack and the Oculus22’s stainless-anything-goes chemistry at the top on practical grounds. For a second can that will live permanently on one host, weight and length matter more. The FLOW 22 Ti is the interesting outlier: it targets the blowback that makes suppressed semi-auto rimfire dirty in the first place.

3.7 The Other Rimfire Cartridges

A .22 LR can that is also rated for .22 WMR, .17 HMR and 5.7×28 — as the VAPOR and the Mask HD are — is worth having, because those cartridges are considerably more energetic than .22 LR and a can rated only for .22 LR should not see them.

Figure 4 — Dimensional drawing of the .22 Long Rifle. A heeled, outside-lubricated lead bullet is the reason a rimfire can fouls the way it does. Source: commons.wikimedia.org, public domain.

Note that .22 WMR and .17 HMR are supersonic in every normal loading. A can on them is a comfort device, not a quiet one, and no subsonic option meaningfully exists. The .17 HMR in particular is a small, fast, loud cartridge and stays loud.

5.7×28 is a centerfire cartridge in a rimfire-sized package and needs an explicit rating; do not assume.

3.8 The Backpacking Case

The .22 Rimfire dive Volume 11 works through a suppressed Ruger 10/22 Takedown as a backpacking rifle. The suppressor side of that argument in brief:

The can is 4 ounces and rides in the pack half. It is the cheapest capability on the whole rig.
A takedown rifle plus a can is a packed-length problem, not a weight problem. Measure the actual packed length with the can attached to the barrel half.
Subsonic through a can, on a takedown host, means a rifle you can shoot without announcing it — which for small game is the whole point.
The BDC reticle problem documented there is a suppressor problem in disguise: the reticle is calibrated for hyper-velocity ammunition and he shoots subsonic. Because the scope is second focal plane, dialling magnification down increases the MOA each circle subtends, which is the correction needed. Those figures are estimates and need verifying on paper.
Record a can-on/can-off zero offset per host. Six hosts, one can, six offsets. This is the number nobody else’s data can give you.

3.9 Bibliography

Mack Brothers, VAPOR 22LR – 5.7x28 Rimfire Suppressor — 100% titanium, 5 3/8 in, 4.3 oz, eight K-baffles, integrated disassembly tool. https://macbros.com/product/vapor-22lr-5-7x28-rimfire-suppressor/ ; https://macbros.com/suppressors-4/ ↩
Mack Brothers, suppressors page — MB762 and MB556 production ceased 2024, “but will still service and repair them.” https://macbros.com/suppressors-4/ ↩
Lyman Sonicore Skarv 22, $199, introduced SHOT Show 2026. https://www.lymanproducts.com/skarv-22 ↩