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BB 147s and CZ..


DirtyB

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Trying to work up a load for my Shadow 2. 

 

Using BB 147 flat points. 

 

I have fit the bullet into a fired case, seated the case in the chamber and am getting 1.129-1.142 on the OAL using 20 rounds.  

 

A seated/crimped cartridge in the chamber will not rotate unless I'm around 1.104-1.108 OAL, anything above is rubbing when I try to spin the casing. 

 

Do these numbers seem about correct?  I know the CZs sport shorter chambers which require shorter OALs.  

 

Planning on starting with 3.3 grain of N320.  Just seeing if anyone wants to take a look at my numbers before I go loading a couple hundred to test. 

 

TIA.  Not used to this, usually I just use generic book numbers and send it with my X5 Legion(roast me).  Little different for the CZ. 

 

 

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My tanfo stock master I found it like 1.09-1.11 I did some testing with n320 

but I’m using a BB 135tc. They come out to 137g when I weigh em 

 

I was in a rush, But fired 10 of each and this is what I got.  Wrote high and low. Most shots were in between there 

I loaded a bunch at 3.3 and hoping to go test on Friday.   

F714DAB2-0BB7-4158-B766-E58A96BBA3B0.jpeg

Edited by Zachjet
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Stop using “generic” book numbers. They rarely apply to all the different shapes and profiles of cast lead projectiles. 
 

As long as the load is within SAAMI OAL specs (1.00” - 1.169”), fits in your magazine, plunks in your barrel and doesn’t show over-pressure signs…. SEND IT. 

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37 minutes ago, DirtyB said:

Trying to work up a load for my Shadow 2. 

 

Using BB 147 flat points. 

 

I have fit the bullet into a fired case, seated the case in the chamber and am getting 1.129-1.142 on the OAL using 20 rounds.  

 

A seated/crimped cartridge in the chamber will not rotate unless I'm around 1.104-1.108 OAL, anything above is rubbing when I try to spin the casing. 

 

Do these numbers seem about correct?  I know the CZs sport shorter chambers which require shorter OALs.  

 

Planning on starting with 3.3 grain of N320.  Just seeing if anyone wants to take a look at my numbers before I go loading a couple hundred to test. 

 

TIA.  Not used to this, usually I just use generic book numbers and send it with my X5 Legion(roast me).  Little different for the CZ. 

 

 

@DirtyB

After doing the OAL tests on my S2 Orange using your same procedure and the BB 147FP, I had several test rounds that could go out to 1.135"-1.138" easily.  My practice is to reduce the average by the recommended 0.015".  So I ended up with 1.120" in MY BARREL and it worked flawlessly.  Using 124/125g bullets in the same barrel, required me to reduce the OALs down to around 1.108" since those bullets have a different profile/ogive.

 

I think your on the right track; but remember each barrel may end up liking a minor bit of difference in powder weight.  Before loading up several hundred, try loading 30-40 rounds for testing in 10 round tests off a bench, RR, etc.  I would also load up a few at 3.2g and some at 3.4g just for testing purposes.  And make sure you run them across a chrono for solid feedback.

 

Good luck! 

 

:)

 

 

 

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also are you seating in one step and crimping in the next ?  Combination seat crimp dies can be really finicky to adjust. You can start the crimp before the bullet is seated, causing just enough bulge that your rounds occasionally fail plunk test,, leading you to believe its OAL,, when it isnt.
On a Dillon 550, I adjust my seat die to seat and just barely remove the bell so it goes into the last station crimp die easily. I then compare OAL pre and post crimp to make sure nothing moved

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On 10/26/2022 at 11:01 PM, Joe4d said:

also are you seating in one step and crimping in the next ?  Combination seat crimp dies can be really finicky to adjust. You can start the crimp before the bullet is seated, causing just enough bulge that your rounds occasionally fail plunk test,, leading you to believe its OAL,, when it isnt.
On a Dillon 550, I adjust my seat die to seat and just barely remove the bell so it goes into the last station crimp die easily. I then compare OAL pre and post crimp to make sure nothing moved

I seat 9mm rds. with a Lee 2in1 die and have the problem you describe.

Any way to fix the problem?

With my loading set up I have to crimp and seat in one station.

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1 hour ago, dmshozer1 said:

I seat 9mm rds. with a Lee 2in1 die and have the problem you describe.

Any way to fix the problem?

With my loading set up I have to crimp and seat in one station.

not really any perfect solution,, even a perfect adjustment with one piece of brass could mean the next one is off due to length of brass.
trimming brass would work but thats tedious.
Some little things can add up and minimize the problem.
Undersize sizer, combined with almost zero flare, jacketed bullets, and almost no crimp. Basic tension will hold the bullet especially with 147's.
other than that its a timing thing. Kinda a pain.

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2 hours ago, Joe4d said:

not really any perfect solution,, even a perfect adjustment with one piece of brass could mean the next one is off due to length of brass.
trimming brass would work but thats tedious.
Some little things can add up and minimize the problem.
Undersize sizer, combined with almost zero flare, jacketed bullets, and almost no crimp. Basic tension will hold the bullet especially with 147's.
other than that its a timing thing. Kinda a pain.

Thanks.

You are correct about the length of the brass.

I have measured know once fired brass, same head stamp to be as much as .015 difference from each other.

I have measured brass before sizing to grow in length up to .010 after sizing.

You are also correct that it is a pain in the ass!!

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  • 2 weeks later...
  • 1 month later...

Just to update this for anyone who may be looking for info:

 

1.108-1.110 OAL (anything longer didn't spin in the chamber)

 

3.3g N320 and Federal GM small pistol primers. 

 

FPS 938-978 resultant PF of 137-143.  

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I use BB 9mm almost exclusively. Used to use 147 FN now I am trying 135 RN. I used to have some light strikes and fail to chamber of 147 in my tanfoglio but my tricked out G17 eat almost everything. In reading this thread and going over my old notes the big difference with a lot of the posters is I was reloading to a OAL of 1.14 to 1.15 (147 gr FN). I have recently been reloading my 135 RN to to 1.12 to 1.13. No failures in my G17. I know the CZ shadow is similar to the tanfoglio. Question to the posters here should I go with a lower OAL like 1.10 to 1.075 for my tanfoglio.

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My tanfo is more sensitive to primer depth then OAL.  I gotta check my notes. But I wanna say I load to 1.12

Federals seat a lot easier then the ginex or winchesters I have, but if I get good depth. They all go boom.  That being said, I only use federals in matches 

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4 hours ago, waktasz said:

Nope, pretty much just send it out. Patriot Defense did my Tanfo and p10c. Now I don't have to worry about bullet profile or loading very short

 

I sent my CZ out and it's longer but no reamer will touch just forward of the headspace surface.  Maybe shooting it will wear that area down, but I still had to shorten my ammo, just not as much.

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14 hours ago, twodownzero said:

 

I sent my CZ out and it's longer but no reamer will touch just forward of the headspace surface.  Maybe shooting it will wear that area down, but I still had to shorten my ammo, just not as much.

Not sure what you mean by "headspace surface," however what reaming does is move the rifling lands a but further down the barrel so the Ogive will not hit the rifling prior to fully seating of the cartridge in the chamber. Unlike a bottle neck rifle cartridge the chamber "headspace" is where the brass/cartridge shoulder sits, :

nd1l7xY1oOfHMQxjE1J7rZmuOvzF4=&risl=&pid

 

A straight wall pistol cartridge is like this:

headspace-straight-01-768x576.jpg

The headspace of the chamber is not reamed longer only the rifle lands are moved further down the barrel. 

 

In a rifle the lands or throat wears further into the barrel because of the velocity, force and heat of the projectile. A soft coated pistol round will not create any substantial wear after thousands and thousands of rounds. Where a high powered rifle will be worn out in the same amount of use.

 

What's the point? Load your pistol ammo to an OAL which works and don't worry about the rest. 

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1 hour ago, HesedTech said:

Not sure what you mean by "headspace surface," however what reaming does is move the rifling lands a but further down the barrel so the Ogive will not hit the rifling prior to fully seating of the cartridge in the chamber. Unlike a bottle neck rifle cartridge the chamber "headspace" is where the brass/cartridge shoulder sits, :

nd1l7xY1oOfHMQxjE1J7rZmuOvzF4=&risl=&pid

 

A straight wall pistol cartridge is like this:

headspace-straight-01-768x576.jpg

The headspace of the chamber is not reamed longer only the rifle lands are moved further down the barrel. 

 

In a rifle the lands or throat wears further into the barrel because of the velocity, force and heat of the projectile. A soft coated pistol round will not create any substantial wear after thousands and thousands of rounds. Where a high powered rifle will be worn out in the same amount of use.

 

What's the point? Load your pistol ammo to an OAL which works and don't worry about the rest. 

 

The headspace surface of a pistol round is the front of the case.  A finishing reamer might cut the surface near the ogive forward but on my CZ, it was unable to cut the surface just forward of the case where the bullet is at its max diameter, which was the new spot where it interfered.  So I was able to chamber a "longer" round as long as the bearing surface portion of the bullet was inside the case.  I was able to extend my COAL from something like 1.080" to 1.130" though, and that's not trivial.

 

Rifling doesn't just wear from projectile friction; the hot gasses from combustion will wear it, too.  I'm pretty sure even a few hundred rounds opened up my barrel enough that the surface we're talking about is larger than it was when I got the gun.  When I got the gun, it was very tight.  Like ridiculously so in what it'd chamber compared to basically every other gun on the market.

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30 minutes ago, twodownzero said:

The headspace surface of a pistol round is the front of the case

The head space is measured on a pistol round from the surface in the picture I posted to the base of the cartridge where it leaves the chamber just like the image of the rifle round. This, to the best of my knowledge and experience, is the standard method. The throat erosion on a rifle is very noticeable while on a pistol I would challenge you in a hardened CZ barrel to be able to measure with any significance the changes after a couple of thousand rounds of coated lead bullets.
 

I load both high power rifle, tens of thousands of 9mm pistol and from experience throat erosion just isn’t an issue or really noticeable in a pistol. Just consider the difference in heat alone between a 9mm with 3.1 grains of powder drive soft bullet going down a 4.5” barrel and 43+ grain driven 6.5 CM FMJ going down 20+ inch barrel. The temperatures, pressures and velocities are substantially different 
 

What’s the point? Don’t over think this, load an OAL that always fits in your pistol and a PF that meets the needs of the shooting requirements. Now rifle reloading and precision is a whole different game. 


I load my 147 FP for my CZ Shadow 2s (I have more than 1) from 1.10 to 1.12 depending on the brand of coated bullet I’m using. Sport Pistol powder about 3.1 and other of similar burn rate 3.1-3.3 grains to make 133 PF. Currently loading Brass Monkey 150 gr FP for 9mm at 1.125 +- OAL in factory stock un reamed barrels.  

Edited by HesedTech
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