First time user help: 135gr Bayou bullets in CZ

[emjei]

I just tested at a match my first reloaded batch which consists of :

135gr Bayou 9mm
3.1 Titegroup
1.135 OAL for a CZ Shadow
Mixed Brass
Federal primmers
PF 128
11# recoil spring

1st Stage I was feeling like a Pro.....fast transitions and front sigh was easy to track

BUT in stage 2 and 3 I had the same malfunction :  DOUBLE FEED

Changed the ammo to Blazzer and gun ran flawless for the rest of the match

Any Idea what could had cause the feed issue? ??   

PS. I think the OAL is too long since the bullets are showing this marks





Mj

[snakeye]

I'm thinking they actually maybe a little too short...kinda looks like the bullets are hitting the bottom of the feed ramp.  I looked at my records and I show Blazer Brass OAL at 1.155...I would try 1.15 OAL and see how that works....I usually load a lot of my 9MM at 1.15

[emjei]

I'm thinking they actually maybe a little too short...kinda looks like the bullets are hitting the bottom of the feed ramp.  I looked at my records and I show Blazer Brass OAL at 1.155...I would try 1.15 OAL and see how that works....I usually load a lot of my 9MM at 1.15

Blazzer pass the push test on my barrel but the Bayou 135 wont ....... Im afraid that if I go longer they will get stocked.

I read CZ chamber are short

Mj

[1SOW]

MJ,  your Bayou 135 RN is .633" long  ( http://www.czfirearms.us/index.php?topic=62657.0 ); and just going by the pic,  shows a somewhat blunt nose. 

Did you do Wobbly's "Push Test" to check what oal hits the rifling/cone?
Using "spent" "UNsized" cases with that bullet pushed in slightly BY HAND,  press it fully into the naked bbl chamber and then carefully pull it out and measure.  Do this a few times with more than one "Spent unsized" case and that will tell you where that bullet in that pistol hits the rifling.

Load .010" to .015" SHORTER (head space) than that oal that makes contact and they should feed nicely.

It sometimes takes several spent cases to find those expanded enough to let you seat the bullet by hand and still give just a little holding power for the test. 

If you've already done this testing sorry to interrupt.

[emjei]

MJ,  your Bayou 135 RN is .633" long  ( http://www.czfirearms.us/index.php?topic=62657.0 ); and just going by the pic,  shows a somewhat blunt nose. 

Did you do Wobbly's "Push Test" to check what oal hits the rifling/cone?
Using "spent" "UNsized" cases with that bullet pushed in slightly BY HAND,  press it fully into the naked bbl chamber and then carefully pull it out and measure.  Do this a few times with more than one "Spent unsized" case and that will tell you where that bullet in that pistol hits the rifling.

Load .010" to .015" SHORTER (head space) than that oal that makes contact and they should feed nicely.

If you've already done this testing sorry to interrupt.

When I insert a round in the barrel it doesn't fall free ( I need to pull it out with the finger nail )  Thats a sign of too long OAL right     Might that be the cause for the malfunction? ?

Mj

[1SOW]

Sure could be.  THAT test is called the "Plunk" test. 

The "push test" is done before you choose an oal and can save a lot of grief and wasted time.

[emjei]

Sure could be.  THAT test is called the "Plunk" test. 

The "push test" is done before you choose an oal and can save a lot of grief and wasted time.

1SOW......do you know the best OAL for CZ Shadow ?    I know each gun is different but is there a consensus for that OAL ??

Mj

[1SOW]

I don't which forum member gave us the length info,  but maybe he'll see your thread and chime in with his load info.

[1SOW]

There is no BEST oal.  The max possible oal is driven by the bullet weight,  length and nose shape  in THAT pistol's chamber.
The 135 Berry's bullets will load long easily.  A 135 conical nose hollow point might not even load in some chambers.
One load/oal may run great in one pistol and then be a jam-o-matic in another.

Some like to load at the longest oal possible using what works in rifles,  but pistol rounds aren't the same animal.  Each bullet's load including oal needs to be tested for best performance in 'your' pistol for your comp. uses..

If you have a back-up pistol,  make sure your loads are developed for the tightest chamber,  so it'll run in both pistols.
FWIW My 75B and 75 Shadow are about the same chamber size.  My SIG will take a MUCH longer oal for those FP, HP or blunt nose bullets.

[emjei]

Plunk test failed !!!!

Still wondering if that was the caused of the malfunction



Mj

[1SOW]

That failure can lead to failure to feed and/or extract.  I can't vouch for the "double feed" result you're having.

I forgot to add,  IT'S also "potentially" dangerous--especially with a spikey powder like Titegroup.  Pressures will go up fast if it's into the rifling and can still fire.
Since you've chrono'd yours at 128 PF,  that doesn't "look" like a problem unless some of the longer cartridges showed a lot more speed which shows up in max dev and standard dev on the chrono.. 

[emjei]

Next batch will be shorter......now I have to figure out the Powder reduction ....hummm

Mj

[1SOW]

Try the "Push Test" for a starting point.  It's worth the effort.

[emjei]

Will do ^^^ ....thanks

Mj

[Wobbly]

MJ -
There actually 2 things going on that could possibly cause your issue.

? As 1SOW related, the bullets you're using look rather blunt. That's not an issue unto itself, but you have to match the bullet shape to your barrel. 1SOW's explanation was very good and I agree with what he told you. Here's the link to the thread on determining Maximm OAL in a CZ barrel...

http://www.czfirearms.us/index.php?topic=34225.0

That test is written for jacketed and plated bullets. Due to their slightly larger diameter, lead bullets are not going to be as cooperative in this test, but take your time and it can be done.

The Minimum OAL for 9mm Luger seems to be around 1.000", so your best OAL will lie between those 2 numbers. This you can see in the cartoon below...



? Another thing I want you to check is your Taper Crimp diameter. Unlike other auto pistol rounds, 9x19 Luger has a slight taper. If the TC is not set correctly, then the 9mm round can wedge itself into the chamber and become VERY hard to extract. TC is measured on the last 1/32" of the finished cartridge case mouth. Since TC is for the smooth running of the ammo in the gun, its diameter is a function of the chamber, not the bullet. Once the correct TC is set then, you might only need to check it once a year regardless of what bullet you're loading. Typically, the best TC falls between 0.378 and 0.376". It MUST be less than the 0.380" your reloading manual is showing you in the diagram. This you can see in the cartoon below...



That's the 2 problem areas, which if checked and resolved, will be most likely to clean up your feed issues.  If the issue seems to be a reduction in OAL, then we can help you work out your new load mathematically. It won't be exact, but it will reduce your work-up time substantially. Just let us know.


Hope this helps !