:o My First KB!

[Bullshooter]

Unlike many shooters, I like the .40 S&W and now have three pistols chambered in this caliber (a Beretta Elite II 96G, a CZ40B and a new CZ75B Dual Tone). Went to the range yesterday with about 200 reloaded 180 gr. FMJFP loaded into mixed cases (reloaded once) using 5.8 gr. of Clay's Universal and a Winchester small pistol primer. Rounds were loaded to a OAL of about 1.130". After firing about 150 rounds through the CZ75B, I had a case separation! Believe me, that got my attention. It felt as if I got a face full of hot sand and a cloud of really stinky smoke. The bullet exited the barrel (and strangely enough, impacted right next to the previous shot). After a few seconds, I managed to get the slide locked back and the magazine out. The case (minus the head) was still lodged in the barrel. I found the head and there was a clean separation from the case. Searching through the brass (which I had intended to discard anyway) I found almost half of the expended cases showed evidence of bulging by the head.

This is clearly an error (actually several errors) on my part. Carelessness like this could get someone hurt and I can assure everyone that it won't happen again. I know that the .40 S&W is fairly hot and maybe I got lulled into a false sense of security because I usually reload .45 ACP with about 6.0 gr. of Unique behind a 230 gr. FMJ. Accurate and mild.

Lessons learned:

1. Always, repeat always, wear safety glasses.

2. If you load at the high end, inspect your brass frequently for signs of trouble.

3. Approach high end loads cautiously.

4. Don't think you're immune to KBs!

5. Always, repeat always, wear safety glasses.

6. Have these lessons tatooed (in reversed image of course) on your forehead so that everytime you look in the mirror you'll be reminded.

PS - I'm writing this from memory, so if my OAL or charge weight is slightly off I apologize. I have it written in my log at home.

[Scooter2]

If you are going to reload for a .40 S&W, make sure you have a fully supported barrel. If you are not sure, have a gunsmith check it out. Guns without fully supported barrels should only be loaded really light with new or once fired brass. Most reloading manuals assume that the gun has a fully supported barrel.

[Mal H]

First of all, I'm glad you were able to type out your post. It could have been worse.

I wouldn't be so fast as you are to blame yourself for the problem. The load you described, if it is accurate and more importantly if your scale is accurate, isn't overly hot. But it sounds like a check of your CZ's chamber dimensions is in order - it just might be oversized. That's a rare occurance, but it does happen.

A few questions: What brand of casing separated? What brand was the majority of the bulged ones? What are the web and mouth dimensions of an unfired reload and of a fired case from the CZ? Did you check and recheck the OAL of some unfired rounds?

[Edited by Mal H on 05-25-2001 at 11:31 PM]

[Bullshooter]

I use a PACTII electronic scale that I calibrate at the beginning of each reloading session and I weigh two or three charges each box. As long as I have a consistent stroke (I'm using a Lee Pro 1000 with the Lee Auto Disc) it usually only varies around .1 grain.

[jtduncan]

Glad to hear you're fine.

The 180 grain bullet just takes too much space up in the case and increases the risk of uncontrolled pressure curves leading to kabooms.

Only use 135, 155, or 165s in 40SW and stick to fully jacketed bullets.

[Steve Veltrie]

If you do not have one go buy a case gage and check each and every case. If it doesn't drop in pull the bullet and toss the case. The case life of the 40 is not even close to that of the 45 due to the higher pressure.
I shoot min. loads thru my 40 and it's still amazing how many cases end up not fitting in the case gage.

[Johnny Guest]

Bullshooter---

Glad you weren't far more seriously inconvenienced. As a caution to all---

THE LOAD QUOTED EXCEEDS POWDER MANUFACTURER'S SUGGESTED MAXIMUM! USE OF THIS LOAD DATA IS AT YOUR OWN RISK AND NO ONE AT THE FIRING LINE WILL SHARE IN YOUR RESPONSIBILITY IF YOU TRY IT!!!!

This is apparently one of those cases, uh, instances, in which the older data was just a bit too warm. I have some older containers of U. Clays which SHOW suggested max in .40 S&W as 180 jacketed and 6.0 (DO NOT USE) and I loaded probably 1000 of these to this spec. They went okay in my Browning High Power. Then, a while later, Hogden's backed way down and said 5.5 was max. Speer manual number 12 showed 5.9 as max, back in 1994.

Bullshooter, your cautions are well advised, and it would serve us well if we ALL memorized them.

Best,
Johnny

[Big Bunny]

What brand of brass was used?

Also it pays to build up to loads, as every firearm is different.
Ten % at a time maybe?

I find some manufacturer's cases/shells are far thicker at the critical separation area than others(Speer had some of those cadmium "KB-ones" once over here -my advice to the owner was to ditch them immediately and we made attractive key-fobs out of them, as they are so easy( so thin) to drill out for the pivot eye!).
I exclusively use Winchester.40S&W cases and have no problems yet through my CZ-75, even though they are reloaded brass from service Glocks originally and some do have an initial bulge - until re-sized!

At least you are still in one piece... and the strong CZ will be OK too!
It is called 'experience' - I am told :0:.

[Mal H]

Johnny - I absolutely agree with the warning about the load. However, I will restate that the load Bullshooter used is not 'overly' hot (as you proved in your HP). For all of our sakes, I would like to get to the real reason for the KB - a lot of us load for the .40 using Universal. So I will re-ask of Bullshooter for a chamber measurement, before and after case measurements and case brands.

[Bullshooter]

Mal H

I'm working on it, but I also have our triennial ISO9000 audit coming up in a few weeks and five plants to work on. Probably won't even shoot for a few weeks. I'll have to see if my son broke the remaining twenty or so rounds down to recover some components. Cases were a mixed lot, but mostly Speer (I had bought about 10 boxes a few months ago to get the brass).

Thanks everyone for you advice.

[Mal H]

Ah ha. Ok, no sweat. I thought you had forgotten about us. KB's are a serious business as you well know and any tips on things to look out for are always appreciated.

[Clark]

I have had dozens of case failures, and they are expensive and dangerous. I now only try the hot stuff with guns I am ready to sacrifice and with a trigger string. I use a folded over moving blanket to catch the parts. Flying extractors from CZ52s could be deadly, so I don't do this around others.

I have learned some things from the experements: 40 S&W and 357 Sig have almost no safety margin and I do not consider safe at max published load book levels with factory cut chambers.

9x23 and AA loads in CZ52s are not far behind in the thin ice department.

Calibers I have tested with more safety margin are: 7.62x54R, 8x57mm, 32 acp, 32 sw, 380, 9x19, 38 sw, 38 Special, and 45acp.

I have not tested, but it is my guess that the new 2001 357 mag loads from Accurate are in the thin ice catagory.

[WalterGAII]

How'd you get that Glock barrel to work in that CZ? OH, you mean other pistols KB, also. That's news to me.

[Bullshooter]

Walter GAII

Not being a fan of Glock (simply because of the way they look and feel - I admit I've never fired one) I often felt kinda smug whenever I read a (too frequent) story about a Glock KB. The foot is now on the other shoe (or something like that). Seriously, I'm extremely pleased that the CZ is a solid steel pistol. I can't find any damage to the slide, frame or magazine. I'm gonna try to find some time to take it to work and use the borescope to look around in the chamber. I guess if we apply sufficient amounts of carelessness you can get anything to KB. Trust me, several lessons learned here.

[Clark]

If you take a 40sw case and cross section it and push it into the chamber [with the barrel out of the pistol], you will see not only does a Glock 22 have terrible case support, it has a sloppy fit too.

When I measured the case failure threashold of a Glock 22 vs a Kel-Tek P40, I found that the brass in the Glock could take more powder before failure. This was a surprise as the support and fit were better in the P40. Maybe the case diameter streches so far the pressure lowers.

Of coures then, I still haven't figured out why I can get so much more power out of a 9mm than I can from a 40sw before case failure.

[Cheapo]

Clark, I'm glad you're gathering catastrophic failure data and just wish that the "general public" could be trusted with your results.

Are you bucking to get enough "education, expertise and experience" to become a court expert or something?

Anyway, the more power (or do you mean velocity?) at the 9mm case failure point vs. the .40 has got to be the fundamental about pressure in a pipe. We think of total PSI as the measurement, but the same PSI in bigger pipe equals more gross pressure loading. I'd betcha that the "escape route" for 9mm gases is also smaller = less gross loading of the brass.

[WalterGAII]

There was an old ordnance engineer who used to post on this and a couple of other boards that I frequent. He investigated lots of Kb's, and had a pretty dismal opinion of the design of the .40 Sheitz und Weasel. He thought that the round design was fundamentally flawed.

The only Kb that I've had with my Glocks has been with an aftermarket match barrel, so we can't blame Glock's design for that one.

If you ever do have a major Kb, like with a double-charged round, you'll wish that you were shooting a Glock, as opposed to some other brands, from which parts fly in such situations.

[Long Path]

Oh, I didn't have any parts fly anywhere off of my Gvmt. Model, and that was a purty bad one. But I'm glad to hear that Glocks manage to hold onto their parts, too.

L.P.