Suppressor host reviews · editorial reference

Kel-Tec CP33 Suppressed: 33 Rounds and a Blowback Catch

Thirty-three rounds of .22 LR in a pistol is a fun idea. Add a can to a blowback handgun and the fun comes with a few caveats worth hearing first.

Short answer

The CP33 is a 33-round .22 LR pistol sold in threaded-barrel versions, and it can work as a suppressor host. A suppressed blowback pistol tends to push gas and residue back toward the shooter, so plan for eye protection, cleaning and a lot of ammunition testing.

The idea behind the CP33

Kel-Tec built the CP33 around a 33-round magazine, a long barrel for a pistol (retailer listings show 5.5 inches), and a plinking-first personality. It is a .22 LR with a very long magazine, some listings mention an optics-ready slide, and a lot of people who buy one want to stretch out a range session. Our sister site RimfireAmmo has a full CP33 guide covering the pistol, its magazine and optics, so this page sticks to the suppressor angle.

One shopping fact first. The retailer behind our links lists the 33-round magazine, not the pistol. That means we are not going to point you to a specific pistol listing here. What we can do is link the 33-round CP33 magazine and the firearms category so you can look for what is available and locate a transfer dealer for the pistol itself.

Threaded versions exist, but read the barrel description

Retailer listings for the CP33 include a version described as having a black, ported, threaded barrel. Two details are worth pausing on:

Threaded or not. Make sure the model you are buying has a threaded muzzle. A standard CP33 does not automatically accept a suppressor.
Ported barrels. Some CP33 listings mention porting. A ported barrel releases gas upward before the muzzle, and suppressors are designed around gas leaving through the end of the barrel. Whether a given can is happy with a ported barrel is a question for that can's manufacturer, not for this site. Check the manual or ask the company before you assume.

If your pistol is unthreaded, the answer is to buy a threaded configuration, not to alter the one you own. We do not publish instructions for modifying firearms or suppressors.

The blowback reality

Here is the part that deserves plain language. The CP33, like most .22 LR semi-automatic pistols, is a blowback design. The slide begins to open while the bore is still holding some pressure, because that pressure is what drives the action. When you attach a suppressor, the can holds a volume of gas, and some of it can come back out through the ejection port as the slide cycles.

What shooters often describe, and what follows from how the mechanism works, is that a suppressed semi-auto rimfire can put more gas, soot and fine residue near the shooter's face than the same gun unsuppressed. The effect depends on the ammunition, the suppressor design and the individual pistol, so we will not put a number on it. The practical consequences are the same regardless:

Eye protection is not optional. Gas and debris near the face is a reason to be careful with eyewear.
Optics get dirty faster. If you mount a red dot on an optics-ready slide, expect to wipe the window more often.
Wash up afterward. Rimfire residue contains lead. Clean hands and surfaces before eating or drinking.
Plan cleaning time. A 33-round magazine means you will put a lot of ammunition through the gun and can in a session, and both will show it. Our suppressor cleaning guide covers the difference between serviceable and sealed cans, and RimfireAmmo has a piece on rimfire suppressor fouling.

Ammunition: the quiet part that is hardest to pin down

You will not know what runs well in your CP33 until you try it. The pistol cycles a light bullet, and subsonic .22 LR gives the action less energy to work with. Standard-velocity ammunition may feel more reliable but means the bullet still breaks the sound barrier, which brings the crack back into the sound signature.

A sensible way to proceed:

Buy a few different small boxes rather than a single large one.
Note which loads cycle every round and which stumble.
Only after you have a winner, scale up.

The retailer's subsonic ammunition category is a place to browse what is on offer, and our subsonic ammo by caliber guide explains what "subsonic" means for .22 LR. Keep in mind that the bullet sound is only one component of the noise, and the slide of a blowback pistol is not silent.

Is it a good suppressor host?

It depends on what you want from a suppressed pistol.

The CP33 makes sense if...	Think twice if...
You want a lot of rounds per magazine for long, relaxed range sessions	You want a gun that stays clean when suppressed
You enjoy experimenting with ammunition	You want to buy one box of ammo and be done
You are happy to wear good eye and ear protection	You dislike cleaning rimfire cans and pistols
You are patient about finding the pistol through a dealer	You want to click a single link and have it ship

If those trade-offs bother you, the Kel-Tec P17 is a lighter, simpler threaded .22 pistol, and the rimfire rifles in our hosts roundup avoid some of the face-gas issues by sitting farther from the shooter.

Law and logistics

Because the pistol is not in this retailer's catalog, you will probably find it through a licensed dealer in your area, which is also where firearms transfers are processed. For the suppressor, federal rules changed in 2026 and state rules vary widely, so start with our 2026 buying walkthrough and verify your state before you order anything.

Bottom line

A suppressed CP33 can be a good time, but it asks more of the shooter than a rifle host does. Get the threaded version, confirm the suppressor maker is comfortable with the barrel, wear eye protection, and be ready to clean.

Editorial note: This is an independent editorial overview built from manufacturer specifications and publicly available information. We have not performed hands-on testing of the products discussed, and nothing here is a performance guarantee. Verify specifications, compatibility and legality for your own situation.

Frequently asked questions

Does Ammunition Depot sell the Kel-Tec CP33 pistol?

The catalog we link to carries the 33-round CP33 magazine, but not the pistol itself, so we point to the magazine listing and the general firearms category instead.

Is the CP33 available with a threaded barrel?

Retailer listings show CP33 versions with threaded barrels, some of them also described as ported. Read the exact model description and the suppressor maker's guidance before pairing them.

Why does a suppressed blowback pistol put gas in my face?

Blowback actions open while the bore still holds pressure, and a suppressor stores gas that then comes back through the ejection port. The effect varies by gun, ammunition and suppressor, so wear eye protection and test your setup.

What ammo should I use in a suppressed CP33?

Semi-auto .22 pistols can be picky. Try several small boxes of subsonic and standard-velocity loads and note which one cycles cleanly.