CZ and WAC

[Sterling]

Probably been discussed many times before?

I have a Czechmate and a CK Arms Open gun 9mm Major.

The CK Arms will accept a OAL of 1.150 and the CZ a 1.135. I got this by dropping a 1.150 OAL bullet into the CK Arms chamber and it rotated. The CZ needed a 1.135 OAL to rotate.

The 1.150 OAL I load to 7.0 Gr WAC, 124 Gr JHP, Small PP and assorted brass. About a 173 PF in my CK Arms.

I want to load the same for both.

Looking at loading 6.7 to 6.8 Gr WAC, 124 JHP. Small PP, assorted brass and would use for both. What are thoughts on this?

 

Or should I go the other way and ream the CZ so I can use 1.150 OAL for both?

I have a Chronograph, and I can get the PF, But what about pressure, as I have no way of measuring this? If I am under 1450 FPS am I ok with the pressure? Is there any correlation between the two?

Thanks in advance

 

[kneelingatlas]

Full sized guns without holes shouldn't have problems with pressure using WAC under 124s, you should be fine at whatever length passes the chamber check and cycles reliably.

 

That being said, I've found round nosed bullets like the Montana Gold CMJ to cycle more reliably than JHPs in my CZ Open guns.  I also prefer lighter bullets and slower powders (I load 10.5gr Shooters World Major Pistol under a 115).

[AHI]

My first thought is 1.150 is short for a CK/2011 gun. Then that's not your question so. First will

the magazine for the CZ accept ammo say loaded to 1.160 length(gives a little room ). If it will

then I would ream the barrel if not then you may need to go the other way. Load short for the CK.

The short length  less gas load is not going to take advantage of the CK comp and the longer length

with more gas could over gas the CZ.  You're going to end up with a compromised load either way .

A slightly slower powder may be the answer.

[Sterling]

Thanks both Ahi and Kneelingatlas,

I will see if the 1.160 will fit in the CZ Mags. Also try round nose, I have kept the Precision Delta RN for 9mm minor as I shoot and reload both. Makes it easier to tell if a bullet is major or minor. I have not tried a 115 gr yet. Have about 10 pounds of WAC so I would like to use this. I do have spacers in the MBX Mags for my CK Arms, I can take them out.

Ahi what is your recommendation for a OAL CK Arms using WAC ?

[George16]

Before I had my Czechmate barrels reamed to 1.170”, I was loading 124 Gr JHP from PD with 6.8 Gr of WAC @1.145 OAL for 173 PF. After reaming, I was able to load 9.7 Gr of AA7 with 124 PD JHP @1.165” OAL for 171 PF. For 115 JHP from PD, I load 10.4 Gr of AA7 at 1.165” OAL for 172 PF.

 

With regards to the ammo fitting in the mag, I don’t have any problems even at 1.170” OAL. It was the longest I loaded without any problems but settled on 1.165”. Big thanks to Aandabooks for info in tuning the big stick to prevent nosediving of the rounds.

[AHI]

4 hours ago, Sterling said:

Thanks both Ahi and Kneelingatlas,

I will see if the 1.160 will fit in the CZ Mags. Also try round nose, I have kept the Precision Delta RN for 9mm minor as I shoot and reload both. Makes it easier to tell if a bullet is major or minor. I have not tried a 115 gr yet. Have about 10 pounds of WAC so I would like to use this. I do have spacers in the MBX Mags for my CK Arms, I can take them out.

Ahi what is your recommendation for a OAL CK Arms using WAC ?

1.165 to 1.175        what ever feeds best.

my current load

124 PD HP

1.170   oal

7.3 WAC

CCI SPM primers

mixed brass length will very  from 1.166 to 1.177

single head stamp will very from 1.168 to 1.173

PF  173

Edited June 14, 2020 by AHI

[Sterling]

I think it is clear, I need to ream the CZ barrel. Funny I checked both JHP and Round nose at 1.165 and checked the CZ barrel drop test. (Not sure what it is called)  and the JHP would not rotate when seated but the RN would. I put them at that length to see if the CZ mags would be any problem, not a problem at 1.175 OAL I think. Thanks for all of your help, all of you!

1 hour ago, George16 said:

Before I had my Czechmate barrels reamed to 1.170”, I was loading 124 Gr JHP from PD with 6.8 Gr of WAC @1.145 OAL for 173 PF. After reaming, I was able to load 9.7 Gr of AA7 with 124 PD JHP @1.165” OAL for 171 PF. For 115 JHP from PD, I load 10.4 Gr of AA7 at 1.165” OAL for 172 PF.

 

With regards to the ammo fitting in the mag, I don’t have any problems even at 1.170” OAL. It was the longest I loaded without any problems but settled on 1.165”. Big thanks to Aandabooks for info in tuning the big stick to prevent nosediving of the rounds.

Very useful information.

Any thoughts on Magnum primers? I have been using on my 9mm minor and 40 cal limited.

[George16]

I have used magnum primers and there’s no significant difference against regular primers. I got 15-20 FPS increase on average.

[AHI]

Biggest advantage I got from magnum primers was lower extreme sped and stranded deviation.

[selecw]

Ream both guns. It is easy to do. In the Czechmate I am running at 1.170 oal with Everglades 115 FMJ. 7.9gr of WAC makes 171-173 PF. I tested the profiles of a lot of bullets.
 

I use the same load in my Atlas Chaos and it makes 169 PF btw.

[Sterling]

Thanks selecw. What reamer did you use, where did you get it? Think there are several reamers for 9mm?

[Sterling]

On ‎6‎/‎14‎/‎2020 at 9:36 AM, kneelingatlas said:

Full sized guns without holes shouldn't have problems with pressure using WAC under 124s, you should be fine at whatever length passes the chamber check and cycles reliably.

 

That being said, I've found round nosed bullets like the Montana Gold CMJ to cycle more reliably than JHPs in my CZ Open guns.  I also prefer lighter bullets and slower powders (I load 10.5gr Shooters World Major Pistol under a 115).

Kneelingatlas-what would you recommend for a 115 gr FMJ Precision Delta and WAC for my CZ Czechmate? Assuming I do nothing but run two different bullets and OAL?

[kneelingatlas]

2 hours ago, Sterling said:

Kneelingatlas-what would you recommend for a 115 gr FMJ Precision Delta and WAC for my CZ Czechmate? Assuming I do nothing but run two different bullets and OAL?

 

What do I recommend for an OAL?  You're going to need to determine that with your own barrel, if you want to load longer the tool is called a "throater", send me a PM if you need help getting it done.