CZ 22 chambers...Std or Match ?

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boxhitch

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Is a match chamber really a better choice?
Are their more difficulties involved when choosing ammo?
are they worth the trouble overall?
PRS rifle
 
If you want to stay with the factory pipe, the match chamber is the better option to start with. not seen any issue feeding SK/Lapua type ammos.

If you plan on reaching out in PRS, then the barrel spec and ammo choices are pretty defined. Let me know if I can help with set up.

Thanks

Jerry
 
The question is whether a CZ match chamber is worth it.

CZ offers a match-type chamber in some of its mass-produced factory rifle models. What does that mean?

It means the CZ match chamber is going to be not as long as on CZ models with standard CZ bolt action .22LR rifle chambers. It also means that in the match the bullet will engage the rifling of the bore, whereas with the standard CZ chamber the bullet will engage the rifling not at all or only a very little bit.

A standard CZ chamber will allow the chambering of a wider variety of ammos. Inexpensive and bulk ammos will have a wide range of dimensions which will fit in chambers that have generous dimensions. These ammos can't be expected to shoot accurately. A match-type chamber will welcome ammo that's made more uniformly to CIP/SAAMI ammo specifications. Such ammos are match-type ammos and these can be expected to shoot much better than other .22LR ammos.

While match-type ammo can be easily shot in a non-match chamber, a match chamber offers a better beginning for accuracy.

The match chamber in a CZ rifle will not in itself make the rifle more accurate, but it can contribute. As far as the rifle itself is concerned, accuracy will be more the product of the quality of the bore. Not all bores are equal, however, especially on mass-produced factory rifles.

For the best potential for accuracy, a match chamber with match-type ammo is the basic and necessary starting point.
 
I get what the potential should be in theory, and being relegated to using premo for best results
doing some digging to see if the premium stuff is dimensionally different and whether all 'match' labelled ammo is this same dimensions or just sales hype
seems not all 'match' is created equal
 
from another site
22LR Chamber Dimensions

Type______Length__Mouth Dia._Throat Dia.
Sporting____0.7751"____0.2307"____0.2270"
Bentz______0.6900"____0.2270"____0.2255"
Match _____0.6876"____0.2267"____0.2248"
Win 52-D___0.5800"____0.2278"____0.2248"

The "Ruger" 10/22 factory chamber is the "Sporting" chamber above.
The "Bentz" chamber is the 'match' chamber for semi-autos.
The "Match" chamber is for bolt actions.
The "Win M52-D" is a bolt action target rifle.

.22 Long Rifle Headspace: .0425" GO // .045" NO-GO
Click to expand...
 
Min and Max SAAMI specs for the .22LR chamber. Rear of the chamber is .2300 -.2320. Forward section of the chamber before rifling is .2260 - .2280.
Click to expand...

A Sporting .22 LR chamber is .8751 in length from the bottom of the rim to the top of the throat compared to .6876 for the Match chamber. The length of the Sporting chamber from the top of the rim to the start of throat is .818 compared to .643.

The Sporting chamber at the base of the cartridge is .2307 wide compared to .2267 for the Match chamber. At the throat the dimension of the Sporting chamber is .227 versus .2248 for the Match chamber.

Rim thickness in both is .043 min and .051 maximum.

What this means is that the sporting chamber is substantially larger than a match chamber designed to shoot high quality ammo. High quality ammo, despite being produced to tighter specs may not shoot well in larger "Sporting" chambers due to improper headspacing, chamber slop, etc.

What it also means is that low quality ammo may not even fit in match chambers because it is designed to be oversized at the factory to fit sporting chambers. Find the right ammo for your sporter and you may be able shoot good groups with a sporter.

Buy a rifle with a "Match" chamber, use high quality match ammo and you will be able to shoot tiny groups. Match ammo has very consistent rim thicknesses, powder charges, bullet seating, bullet weight, bullet length, etc. A match chamber gives you the potential to shoot championship groups.

There are "accuracy nuts" who have found very the most dimensionally perfect ammo for their Sporting chambers allowing them to shoot small groups. The variable comes in when there are inconsistencies in the ammo.

Dimensions from SAAMI and published in the Small Caliber News, Winter Edition 2003. Vol. 6 No. 4.
Click to expand...
...............
 
The 22 Winchester Rimfire is a different round and not the same as 22 Long Rifle.

SAAMI and CIP set the specs for ammo and chambers. SAAMI generally applies to North American factory rifles. There is a SAAMI Sporting chamber and a SAAMI Match chamber. CIP, which includes most European firearms makers, has one set of specs that establishes the minimum/maximum dimensions allowed.

Note that every CZ .22LR will follow CIP specs. The chamber dimensions shown below for CIP are the minimum allowed. The CZ match chamber will be closer to the minimum dimensions permitted by CIP while other CZ bolt action rifles will have longer chambers.

There are a number of Match chambers that are made for custom barrels, and some of them are shown in the last image.

CIP 22 Long Rifle, below.



Below, SAAMI Sporting chamber and Match chamber specs.




The reamer dimensions for some custom Match chambers as well as others.

 
Based on the CIP minimum chamber info provided, and that "tightest specification that CIP will allow" = "CIP minimum chamber" then:

Dimension A = .2268"
Dimension B = .2252"
Dimension C = .6000"
Dimension D = 5 Degrees
Dimension E = .288"

would be the CZ match chamber dimensions for the 457 MTR and 457 LRP.

Note, CIP Bore minimum dimensions are tighter than SAAMI and Lilja "tight".

CIP Bore = .212"
Lilja "tight" Bore = .215"
SAAMI Bore = .217"

CZ Bore = .211" - source https://cz-usa.com/support/faq/

A: Our 22 LRs use our cold hammer forged and lapped barrels, and are built a bit tighter than many other guns. In 22 LR we run a .211 bore, which is one of the reasons our .22s are known for incredible accuracy. This also means that a .17 or .20 rod and jag are required for cleaning, since a .22 rod will be too large.
 
boxhitch said:
Based on the CIP minimum chamber info provided, and that "tightest specification that CIP will allow" = "CIP minimum chamber" then:

Dimension A = .2268"
Dimension B = .2252"
Dimension C = .6000"
Dimension D = 5 Degrees
Dimension E = .288"

would be the CZ match chamber dimensions for the 457 MTR and 457 LRP.

Note, CIP Bore minimum dimensions are tighter than SAAMI and Lilja "tight".

CIP Bore = .212"
Lilja "tight" Bore = .215"
SAAMI Bore = .217"

CZ Bore = .211" - source https://cz-usa.com/support/faq/

A: Our 22 LRs use our cold hammer forged and lapped barrels, and are built a bit tighter than many other guns. In 22 LR we run a .211 bore, which is one of the reasons our .22s are known for incredible accuracy. This also means that a .17 or .20 rod and jag are required for cleaning, since a .22 rod will be too large.
Click to expand...

CZ doesn't publish information about the exact dimensions of their "CZ match chamber". It's not necessarily the minimum CIP dimensions. It can be taken as a given that it's smaller than standard CZ chambers.

CZ doesn't have a .211" bore. That wouldn't be permitted under CIP. CZ seems to have rounded down.

Below is a chart made and provided by CZ. It compares the CIP specs with those of SAAMI. For convenience, 5.38mm is 0.2118".

 
Lots of guys shooting cz factory match and non match barrels in prs. Lots of them shoot just as well as the custom barrels.
From what I’ve seen the only reason to move away from a factory cz is for weight and balance.
 
I shoot a 457 Varmint 20” non match chamber in my local orps/Crps matches. It hangs with anything else on the line when shooting SK standard or rifle Match. But... it has a nasty cold bore shift, especially when the temperature is low.
First shot is always 1.5” low at 50 yds
I’ve tried everythingthat I know of. headspace, carbon ring, action torque. And can’t seem to get to the bottom of it. After struggling with this issue for a year I’ve finally pulled the trigger on a 22” schnooble IBI.
I’m looking forward to pushing the balance point a bit further forward, and of course a little more consistency.
 
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