How and when to clean your CZ 457 (or other CZ rimfires)

A CZ 457 will last you decades and keep shooting tight groups, but only if you look after it. And rimfires have their own rules, because rimfire ammo behaves differently from everything else. Here is how we clean ours after a range trip, when it is worth stripping the rifle down properly, and which small parts wear out and are worth keeping in a drawer.

Written for the CZ 457, works on the older ones too

The CZ 457 is the rimfire that passes through our hands most often, so everything below is written with it in mind. Whether your CZ 457 comes in .22 LR, .22 WMR or .17 HMR, this article will work for you.

And if you shoot one of the older CZ rimfires, you can use this information as well. The CZ 455, CZ 452 and CZ 512 need exactly the same treatment. The only thing that differs is how you get the bolt out, but I am sure you already know how to do that anyway.

TIP: If you shoot a CZ pistol as well, I covered that one separately in How to clean your CZ pistol: Frequency + cleaning tips.

Safety first

This one applies to every gun you will ever pick up:

Before you touch anything, drop the magazine, pull the bolt back and look into the chamber. Then look again.

What makes a rimfire different

Rimfire bullets are lead, coated in wax or grease. After the first 10-50 rounds that wax leaves a thin film in the bore, and the rifle shoots better with it than without it.

That means that scrubbing the barrel out every time you come home from the range actually works against you. You strip that film only during a deep clean, once accuracy starts to drop off.

The chamber is where you want to spend your time instead. Wax, grease and unburnt powder bake together in there into a hard crust. Once it builds up, rounds stop feeding cleanly, the bolt gets stiff to close and cases start sticking on the way out.

Never dry fire it

On a rimfire there is no primer in the middle to stop the firing pin, so the pin slams straight into the edge of the chamber. Do it often enough and you will either bend the pin or peen the chamber mouth. Neither one is something you would like.

Cleaning up after the range

Nothing complicated here. Five minutes and you are done.

What you need:

• a bore snake in .22 LR, dry, no chemicals,
• a short brass brush, or an old toothbrush (once it goes in the cleaning kit, it does not go back in the bathroom),
• cotton swabs,
• gun oil,
• a microfiber cloth.

How we do it

1. Drop the magazine and check that the chamber is empty.
2. Take the bolt out. On the 457 it lifts straight out, on the older models the procedure differs slightly, so check your manual if you are not sure.
3. Start with the chamber. Put a drop of gun oil on a cotton swab and wipe the carbon and burnt wax off the chamber mouth, then go over it with a dry swab until it comes out clean.
4. Run a dry bore snake through the barrel once or twice, always from the chamber towards the muzzle. No solvents and no degreaser at this stage, you still want that wax film in there.
5. Brush the bolt face with the brass brush or the toothbrush, and dig the deposits out from under the extractor and cartridge retainer with a dry swab.
6. Wipe the bolt face with the microfiber cloth and a drop of oil.
7. Put it back together and wipe the whole rifle down with the cloth and a drop of gun oil. That gets your sweat and fingerprints off before they turn into rust.

When does it need a proper strip down?

Three occasions, in our experience:

• before the rifle goes into the gun safe for a few months,
• when it starts losing accuracy, usually somewhere around 1000-3000 rounds,
• when it stops behaving: light strikes, cases not ejecting cleanly, a bolt that drags.

What you need for the full strip

• a cleaning rod, sectional or one-piece,
• a bore guide,
• a bronze or brass brush in .22 LR,
• lead and carbon solvent,
• cotton patches and a jag,
• gun degreaser,
• gun oil.

How to do it

I.e. how to take care of each part in your CZ 457.

Bolt

1. Take the bolt out and strip it down into its parts.
2. Degrease everything, then work the carbon and wax out of the extractor and cartridge retainer grooves and the firing pin channel with the brass brush.
3. A light film of oil and back together it goes.

Barrel

1. The bore guide goes in where the bolt was.
2. Wet a patch with lead and carbon solvent. (BoreTech Rimfire Blend is made for rimfires, Hoppe's No. 9 Gun Bore Cleaner does the job too.) Push it through and let it soak for as long as the label says.
3. Screw the bronze brush onto the rod and push it through several times, always from the receiver towards the muzzle. Never scrub it back and forth.
4. Continue with dry cotton patches until they come out clean.

Trigger mechanism and magwell

1. Take the barrelled action out of the stock, which means undoing the action screws.
2. Sweep the debris out of the trigger. A brush or a puff of compressed air does it.
   *On the 457, note where your trigger adjustment screws sit before you start, so you do not knock a setting you were happy with.
3. One small drop of oil on the sear pin. One only is enough, because oily sear collects dust and you will be back in full cleaning of your CZ sooner than you wanted.
4. Blow the magwell out with compressed air, or scrub it with the toothbrush.
5. Wipe the inside of the magwell with cotton swabs or a cloth soaked in degreaser.

Putting it away

Push a patch with a drop of gun oil through the barrel. Leave yourself a note if you need one, because that bore has to be wiped dry with a clean patch before you shoot again.
Wipe the outside down with a cloth and a little preservative oil, just enough for a thin film. Then reassemble it and let it sleep until next season.

WARNING: A full strip takes the wax film out of the barrel with it. On your first trip back to the range I recommend to give it 30 - 50 rounds before you start judging your shooting results.

Consumable parts - which spare parts are worth keeping in stock

The 457 is built tough and very little on it actually breaks. A handful of small parts do wear, though, and they tend to announce it by messing with the way the rifle runs.

Magwell

The original polymer magwell has a tendency to break. These are then sometimes hard to get, so I would recommend getting one spare upfront.

You can have either the original magwell (here), or you can buy a life-long solution by getting a metal magwell instead (see here).

Firing pin and firing pin spring

The pin takes a beating on every shot, and so does its spring. How to know you need these parts? Faint marks on the case rim, or the odd round that just clicks.

TIP: Dry firing is what kills these parts. If you want to practise the trigger at home, use rimfire snap caps.

Extractor, cartridge retainer, and their springs

These two claws on the bolt face pull the case out of the chamber and steer it towards the ejector. They go blunt with use. When cases start staying in the chamber or flying off somewhere unexpected, this is usually the reason.

I recommend keeping a spare set in the range bag. They cost next to nothing and can save you a wasted afternoon.

Magazine springs

Last round jamming on the way up, or a bolt that will not quite close? The magazine spring has probably gone soft. Compare it against a magazine you know is good.

TIP: Replacement springs for CZ 457 magazines are in the Magazines subcategory under CZ 457 accessories.

Anything else you can look up by its part number from the manual in the Spare Parts subcategory.

Keep your CZ 457 in top shape

None of this is hard work. It is mostly about knowing which bits of a rimfire behave differently from every other rifle you own.

Leave the wax film in the barrel and let it do its job for as long as the rifle shoots where you point it. Keep the chamber clean. And never dry fire it.

Then, before it goes into the safe for the off season, give it the full strip, a proper clean and a thin coat of oil. It will be ready when you are.