CZ75 Headspacing

[ClemsonAl]

I enjoy shooting my CZ75 so much, that's why I started reloading last year. I fired hundreds of mixed factory rounds without any kind of problems. It functions perfectly. When I started reloading, I went with starting loads at factory ammo COL's. Again, no problems. I have since developed loads that shoot well in all of my pistols.(1.125-1.135)
Then I started reading about using your barrel as a case guage. I also read that CZ's have short throats. I took 8 different factory cartridges and my reloads, and did the barrel test. All of my cartridges seat out past the barrel hood, yet they drop in and out freely. I can also spin them in the barrel and they don't grab onto anything.
If the rounds feed and function reliably, is there REALLY a need for me to load to a lower COL?
I'm guessing that at least half of the CZ owners don't reload, and are perfectly happy using factory ammo with long COL's. You don't hear of many reliability issues with CZ's.
I feel like a sinner on my way to Reloaders Hell if I don't shorten my COL's. ............Thanks, Al :banghead:

 

[rbernie]

The COL issue with CZs (and some BHPs) is related to the short leade/freebore in the barrel. If your chosen bullets can chamber easily at a long COL (as should most any 'traditional' .355 bullet designed for use in the 9x19), then you have not sinned at all.

You may find that if you move to non-traditional bullet shapes (truncated cones or broader ogive/less pointy RN), then you may also have to shorten the COL to keep the bullet from jamming into the rifling before the cartrige is fully chambered.

 

[Jim Watson]

The little projection on a CZ barrel that resembles the hood of a 1911 is not a reference point for headspace. If your ammo, factory or reload, chambers freely in the barrel, the action closes on it, and the loaded round can be extracted easily, you are OK.

 

[ClemsonAl]

CZ75

Thanks guys. I feel better now. I have some Remington 124gn JHP's on backorder and I will definately check their fit in the barrel. Any load suggestions for these bullets? I use Tightgroup,AA5,and 231. And yes, I do have and will check my manuals. Thanks again.....Al

 

[amlevin]

I have a CZ75 SP-01 that gave me some trouble with OAL initially. Some HP's I loaded would not fully chamber, keeping the slide from going fully into battery, at the recommended OAL of the powder manufacturer. Vihtavouri insists that the OAL for just about every bullet they show needs to be 1.142" using 3n37. I can't load much above 1.130 with Montana Gold 124gr JHP's or 124 gr GDHP's. Even at max load with 3n37 I don't have any pressure issues and the pistol works flawlessly.

 

[larryflew]

My CZ's have only had that problem with Montana Gold 124 JHP because of the truncated cone. I have to load those shorter than usual.

 

[rcmodel]

Color your bullet with a black Dry-Erase or Magic-Marker, or Candle smoke, then chamber it.

Any rifling or leade contact will be readily apparent where the marker rubbed off the bullet.
Then just keep coloring and seating deeper until it doesn't.

rc

 

[918v]

To properly chamber check a reload is to feel the case mouth bottom out against the chamber and then spin the bullet in the chamber while feeling for the bullet nose for rubbing against the rifling.

If the bullet is hitting the rifling, the round will not spin in the chamber very easily.

 

[soloban]

I reload for my CZ-75B. I run all my loads through my Lee FCD and haven't had a single problem. Good accuracy too.

 

[Rule3]

I only have problems with the CZ and GHP when using lead RN bullets. Either 115 or 124. Due to the round head of the bullet I need to reduce the COL to 1.075 before they will drop in and out of the barrel and chamber correctly.

Regular FMJ with a more pronounced point to the bullet are not a problem.

 

[CZ57]

I have some Remington 124gn JHP's on backorder and I will definately check their fit in the barrel.

When I reloaded Rem. 124 gr. JHPs for my CZ P-01, they would touch the rifling at 1.127" so I backed off .005" for an OACL of 1.122"/28.5mm and they were very accurate with several different powders.

 

[1SOW]

rbernie: What he said is true in my CZ 75B

MG 124JHP: 1.1 MAX oal to not contact rifling
Zero 125JHP: can go a skosh longer than 1.1" but I use the same as the MG.
Berries 124 plated HP: needs to be much shorter--from memory was 1.06-ish

Most fmj RN can load out to SAAMI max with an occassional exception, but I load shorter--usually 1.125-1.135.

 

[1SOW]

amlevin:

Vihtavouri insists that the OAL for just about every bullet they show needs to be 1.142" using 3n37.

No sir, they don't. They show you their test results including speed and pressures "at that oal".
Their firing mechanism is not even a pistol. It's a device to measure all the speeds and pressures involved.

If you load at that oal OR LONGER you will have that pressure or LESS. If you need to load shorter, you will have to lower the powder charge and work up the new load starting low--one shot at a time to see if it cycles your action.

Hope this makes sense.