CZ 75B 9mm Problem with BLAZER Alum Ammo??

[1SOW]

I've fired over 1000rds of WC, Rem & various Reloads (all range ammo) without any jams or FTEs. I had never tried Blazer ALUMINUM 115 FMJ.

Yesterday I changed the stock 14# recoil spring to a Wolff 15# as well as the stock 20# trigger spring/mainspring to a 15# Wolff. BIG improvement with DA and SA.

Today I shot a 44 rd total mix of Winchester white box 115 FMJ and 24 rds of it Blazer Aluminum 115 FMJ in a USPSA league shoot. I had "2" FTE's both with the Blazers. My time went to *!## and gone.

The aluminum cases came out far enough to cock up and jam against the next mag round. I had to pull on the spent case to get the mag to drop.

Has anyone had a problem with Blazer aluminum in the 75B?? or could my new recoil spring have anything to do with it??

 

[Snarlingiron]

A good friend of mine has 2 Cz's, straight stock, and they simply don't "like" the Blazer aluminum. Any brass cased ammo seems to work fine. There are 3 of us in our group that shoot Glocks, and we have shot literally thousands and thousands of rounds of the Blazer aluminum stuff without any problems. It's kind of like "Doc, it hurts when I do this."..."Don't do that."

 

[The Lone Haranguer]

My own PCR had two failures to extract/eject in 50 rounds of Blazer aluminum, and one with some Blazer Brass. It has not done this with any other ammo. I recently shot (in different sessions) 200 rounds of Independence FMJ and 100 of the Remington "green box" JHPs without a single failure.

 

[1SOW]

Fool me once, shame on you. Fool me twice , shame on me!

 

[The Lone Haranguer]

The aluminum cases came out far enough to cock up and jam against the next mag round.

That's what mine did, in one of the failures. In the other, the mouth of the case did not even clear the front of the ejection port. It made quite a mess - I had to pull back and lock the slide, eject the magazine and shake the case out so it fell through the magazine well.

Since its only failures have been with that ammo, I am inclined to blame ammo incompatibility.

 

[wally]

I'm inclined to blame the changed mainspring. The mainspring has more effect on the gun's timing than does the recoil spring.

My stock CZ75B and CZ75B Compact have shot little besides CCI aluminum Blazer or Wolf/Monarch steel cased ammo, (remember up to about 20 months ago this stuff was $80/1000 rounds arround here) with no issues.

It may work with other ammo, but this suggests to me you've made the gun less reliable overall.

--wally.

 

[The Lone Haranguer]

(whistle)

 

[ikelo]

blazer aluminum stovepipes are very common w/ cz's.

my p-01 can't shoot a mag of blazer w/o at least 3 stovepipes. it is 100% w/ brass though.

 

[barneyfife.357]

I will add to the solidarity, I purchased 50 rounds of blazer and I don't think a single round fed/ejected correctly in my beretta, sig, or CZ--the only gun I have ever witnessed to shoot the stuff is a High Point carbine in 9mm, go figure

 

[1SOW]

Wally:

I'm inclined to blame the changed mainspring. The mainspring has more effect on the gun's timing than does the recoil spring

Okaaay...AFTER the hammer drops,... the floating/inertial firing pin is hit and moves forward to impact the primer,.... the bullet fires and hits the "A" zone, while the slide is blown back ....which then....?

I'm not being sarcastic, I'm still learning and appreciate the help. Where does "timing" come in after the bullet has left the barrel?

 

[P. Plainsman]

This is evidently a pretty common experience with CZ 9mms -- they don't like aluminum cased ammo.

Both my CZs (75B and P-01) do the same thing reported by the original poster. They're extremely reliable guns with brass ammo; with aluminum cased Blazer, they suddenly give feeding failures. They have stock springs. I am thinking about trying some increased-power Wolff extractor springs.

 

[Deer Hunter]

Mine does that sometimes. It was worse when the gun was new though.

 

[wally]

The timing comes in with making sure pressure has dropped to a safe level before the slide moves back enough to unlock the barrel and start the extraction/ejection cycle. If the pressure is too high when the barrel/slide unlock, extraction failures are your first warning sign. Another is the brass bulges more or less uniformly as opposed to only in the crescent shaped unsupported area of the chamber -- look at blowback .380ACP empties most will show "ring" near the base instead of the slight taper from base to neck it had initially. When your 9mm starts doing this you are getting too close to the edge IMHO.

The hammer/mainspring provides most of the resistance to delay initial slide rearward movement, the recoil coil spring offers much less resistance initially as you can easily feel from the difference in racking the slide with the hammer back vs. hammer down. Excessive initial slide velocity can beat up the gun, a stronger recoil spring can help, but then it beats on the gun more in the other direction when chambering a round.

From his description, the empty remains partially in the chamber which makes it an extraction failure. If the empty is 100% out of the chamber then its a stovepipe, which is an ejection failure.

If it works with brass cased ammo *and* the empties still have a more or less uniform taper (ignoring the unsupported chamber area) You can probably be happy just not using aluminum cased ammo but if your brass is expanding much beyond the case head diameter I'd reconsider that 25% lighter mainspring change.

I'm willing to admit some CZ75Bs may not like aluminum Blazer, but mine have no issues with it and have shot little else. I'd be curious if you have the same issues with the factory springs. Generally change one thing at a time -- springs or ammo first, then the other so you have a better clue as to what caused the issue if there is one.

--wally.

 

[DMK]

Has anyone had a problem with Blazer aluminum in the 75B?? or could my new recoil spring have anything to do with it??

I've had my 9mm CZ75B (a 1996 model) for about 7 years and a CZ40B for about 5 or 6 years. I'm cheap, so most of the ammo through them are aluminum Blazer. Never had any problems. I don't keep track of how many rounds, but at least a few thousand Blazers through each gun, the CZ75 probably has 4-5K through it total.

In fact, the only rounds that have ever given me problems are S&B and Winchester. Less than 5 jams in the CZ75B since I owned it (I can think of three), and all were definitely bad rounds. I can't remember the CZ40B ever jamming once.

I have stiffer Wolf recoil springs in mine (in both guns). I also have stiffer Wolf springs in the mags. Mainspring and extractor springs are OEM.

 

[Tecolote]

I had 2 CZ75Bs that fed Blazer just fine. Not a single problem with either.

 

[P. Plainsman]

We had a sizable thread about this very issue a month ago.

http://www.thehighroad.org/showthread.php?t=323894

Notice that the majority of those who posted -- eight or nine different users -- reported trouble with aluminum cased Blazers in their CZs.

If yours doesn't choke with 'em, that's excellent, but it's pretty clearly an issue worth taking into account. I am a huge CZ fan, but I wouldn't recommend one to somebody who wants to shoot mostly Blazer aluminum.

 

[brentwal]

BLAZER!!!!

 

[1SOW]

wally
Thank you , It's easy learn when you know as little as I do, but you gave some good info.
The case was ALMOST out and cocked up 30 degs or so & jambed against the next mag round.
The slide impact increase with a 1lb increase in recoil spring weight should be negligable when chambering a round. I quit releasing the slide on an empty chamber some time back when I heard reports of the damage it can cause.

One thing I completely agree with is that I changed too many things at one time. Circumstances had me short on ammo and blazer is what I could find. I may change the trigger spring back to check, but only the aluminum seems to be affected. It threw the brass 6' or more.

That change down to 15# (or even lower) hammer spring is a common change with CZers who compete. Jim Miossi, Angus Hobdell and others recommend it to be safe to at least down to 15/16#. The DA trigger pull is dramatically better and single action is lighter too. I'ts like getting a $200 action job for $4.98
ONLY using light target/range ammo, I went up slightly to the 15# recoil spring from Wolff. Mostly to decrease percieved recoil and improve my double-taps. I was afraid to go higher for possible FT Extract problems.
Another issue is that the springs require a number of cycles to "set". It may still change.

I was looking for and got enough feedback to see this isn't rare for aluminum rds especially with CZs.

I'm saving brass, so I'll watch for the indicators you mentioned.

Thanks again,
Don

P.S.I loaned my son my Sig and Blazer ammo to shoot today and as usual it eats anything you feed it just like my son.

 

[JohnKSa]

VEEEERY interesting...

I bought a CZ75B awhile back and did a review/range report for another forum.

http://www.therallypoint.org/forum/index.php?topic=1298.msg7762#msg7762

In the last paragraph of the review I noted that I experienced a single malfunction, a "stovepipe", during the testing. Using Blazer Aluminum. I've updated it to reflect other reports of problems with that ammo.

 

[ikelo]

i'd like to add that my p-01 has had the extractor spring replaced with a wolff spring and the mainspring was replace with a wolff 17 pound spring.

after switching to the wolff springs, i actually had more frequent occurrences of blazer aluminum stovepipes than with the factory springs.

i have never had a malfunction with any brass ammo.

 

[wally]

I may change the trigger spring back to check, but only the aluminum seems to be affected. It threw the brass 6' or more.

How far was the brass flying before the spring changes? A significant increase in how far the brass flies compared to the factory springs is an indicator of potentially excessive slide velocity.

Save some of the empty brass with this spring setup and compare to the factory setup if you switch back -- look for loss of taper near the cartridge base when comparing mod to factory setup. If the pressure is high enough to expand the brass during extraction when the gun unlocks, I'd stick with the factory springs unless you are willing to reload to a lower power level.

I'm a big believer in "if it ain't broke, don't fix it!"

Make sure the competitors you mention are not shooting compensated guns or reduced loads with the very light springs -- the extra mass of the compensator hanging off the barrel slows things down a lot.

--wally.

 

[Pilot]

Blazer aluminum is the one ammo I stay totally away from for any of my semi-auto pistols.

 

[rbernie]

Blaser aluminum ammo can work just fine in a CZ75B - just upgrade the extractor spring with the more robust Wolff unit. I have, uh, more CZs than fingers and that's fixed every single one of 'em 100%.

 

[Gary G23]

I concur with rbernie 100%.

 

[1SOW]

Thanks to everyone for the feedback

wally:
Because I was moving I don't know the exact distance it was throwing brass. This weekend I'll shoot at the range before my league shoot. I'll salvage and check the 'brass'. I'll also have my son on my right and see if it still throws the brass down his shirtcollar.
I am curious about one thing. If I had been shooting high pressure +P+ loads with the stock springs, would that cause problems like you mentioned with the slide moving faster? The stock pistol & springs were supposably able to handle those pressures. I'm now shooting the lightest factory loads available that I know of.
If Aluminum turns out to be the problem, I may try a new Wolff Ejector Spring

I'm a big believer in "if it ain't broke, don't fix it!"

For guns that my life may depend on, I mostly agree. For my fun guns I definitely don't agree. "Fix'n" it to be faster, prettier and shoot more accurately is a big part of the fun for me". I'm about to do a light polishing with 600, 800, 1000 & 1200 wet paper on the CZ's sear, ejector, hammer hooks and some surfaces with metal-to-metal contact. I hope I'll be as happy with it as I am my High Standard .22 I bought and 'fixed' in the 70's for a Bullseye shooting league. It has a scary trigger that still works flawlessly, but I don't shoot Stingers in it.

Again, thanks for the info.