Question on 40's

Status
Not open for further replies.
PWC

PWC

Member
Joined
Feb 20, 2018
Messages
1,814
Location
Central AZ
I have read several places where case heads have let go, I don't know if it is the same occurance being posted in multi places or not. I have no familiarity with 40s except for a friend that shoots them, and does not reload. I've read it is a high pressure cartridge; I assume it is of locked breech disign similar to the 45ACP.

Other than expense, and slightly longer action, is there any reason why the cartridge head couldn't be completly supported like a bolt rifle?
 
Some modern pistols used to have a loose chamber for easier feeding. It's not as sloppy as it used to be though.

Federal, Blazer, and American Eagle run fine in my Glock 23's. I don't reload .40. I have in the past, reloaded it very weak, for competition. .40 is huge in pistol sports that need to make "major" power factor.
 
Almost all early 40's were built upon 9mm frame/slides.

This quickly became an issue for all the manufactures. Now-a-days manufactures start with something to tolerate the 40 and scale it down to 9.
 
The KB'ing Glock in 40S&W is relatively old news. You can search for pictures of case head support for each Glock generation. If you have one that does not fully support the case head AND you shoot factory ammo, it is safe, but creates "pregnant" brass where the unsupported area of the case expands and is yielded. A person can resize and reload this brass in another gun, with a fully supported chamber, with no ill affects. The problem occurs when someone reloads that pregnant brass AND the case is oriented such that the yielded "pregnant" area of the brass case is in the same unsupported area of the barrel. When fired under those circumstances, THEN the yielded area of the case at the unsupported portion of the barrel has the ability to rupture. Glock has changed their 40S&W barrels to better support the case head. If you end up with an older generation AND want to reload for it, most people just purchase one of the many aftermarket barrels that fully support the case head.

From the gun manufacturer's perspective, it's a balance. Customers would say they want an incredibly accurate gun, that always fires, and will feed every kind of ammo. Unfortunately, we cannot have the best quality for the cheapest price in the shortest timeframe. For a simple example: To feed everything, the tolerances have to be wider for ammo variation at the expense of some accuracy (e.g. Glock). To be more accurate, the tolerances have to be tighter, at the expense of feeding everything (e.g. Kimber).
 
As cougar1717 has pointed out, the problem was mainly with early versions of Glock pistols chambered in .40 S&W shooting hand-loaded or reloaded ammunition, and has since been resolved. Some of the early versions of .40 S&W pistols made by Glock and Beretta used the same slides as their 9 mm Luger versions. This required thinner barrels since the bore of the .40 S&W barrel was some .045" wider. These pistols did not hold up as well as the 9 mm versions which contributed to the notion that .40 pistols were unreliable.

Maximum case pressure specified by SAAMI for the .40 S&W cartridge is exactly the same as that for standard pressure 9 mm Luger cartridges: 35,000 psi. While this is greater than that for standard pressure .45 ACP, it is less than that of +P 9 mm Luger, and 5000 psi less than that of 357 SIG.
 
As a senior weapons trainer, I supervised 2 generations of Glock 40 pistols, totalling 50 guns over 15 years. At least 2000 rounds per gun, per year. (police department) We shot Federal Eagle 165 and 180 as well as Federal Hydra Shok and HST ammo. My personal Glock is fed Freedom remanufactured and white box rounds, and HST. I've never seen a case failure, nor have I heard of one in the surrounding departments who used Glock 40s exclusively. This is just what I have personally experienced.
 
I have fired many thousands of 40 in everything from an early beretta 96 to gen 2 glocks. Of all my 40s the 96 has the least chamber support. Most of my shooting has been factory ammo but once I got a few 5 gallon buckets of brass I did get stuff to set my progressive up for 40 and worked up a mid level plinking load. Ive seen bulging but not enough to bother me and ive never had a 40 case rupture. I don't track reloads in 40 or 9mm I just throw them in a bucket and discard when they are beat but I'm sure some have 3 or 4 loadings. With decent brass the bulging has never been an issue. I don't load hot or even close, I'll use a 10mm for that and factory ammo is cheap enough (blazer brass was recently 60 dollars for 350 rds) that I mostly reload light loads for shooting steel, I use165 gr Plated hollow points over unique at about 975 fps iirc. I worked up some xtp loads for woods carry but that was years ago.
Ive also been given thousands of pieces of brass, some from an instructor for NC police, wardens and state troopers and haven't seen any seriously "glocked" brass although about half was clearly fired from Glock evidenced by the square firing pin indentation.(about 50% percent nickel too) its somewhat sorted but the occasional 357 sig is mixed about.
My experience echoes the above statements. It's a non-issue
 
Thank you all; I don't have a 40 and have no interest in getting one. I was just wondering about the problems I see on the web. The problems usually have mixed in a problem with the plunk test. That seems to set everyone off to buy xtra dies, or not, to remove the bulge, to swadge or not, and all sorts of rabbit trails.

Thanks again
 
I use a standard rcbs carbide resizing die. Adjusted just above the shell holder, like every other caliber. I load for probably 15 different guns from sloppy glock chambers to tight match chambers with the same setup. Never been an issue.
 
HK USP40, SIG P229, CZ40B, all purpose built from the beginning as .40 S&W Service pistols, all have full case support, my Sig an HK are both 1994 models the CZ is a 2000, all will eat out an X-ring at 25 yards if you can shoot

cI3bY5j.jpg
I have about $600 in the Sig, and about $450 each in the HK & CZ
 
There are entities throughout the government that fire hundreds of thousands of rounds of various manufacturers through 40 S&W pistols on a daily basis, mostly through Glock pistols of one type or another. I have never heard of one doing this. If failures of this sort were epidemic, they wouldn't continue to use 40's.
 
I have never seen an issue , a lot came from the older guns with a lack of case support , also added to the mix was poor reloading habits using worn brass and loading with fast powders like tight group getting a double charge by accident not noticing it or getting bullet setback and blowing up their gun. I used to work in the LE field and we shot thousands of rounds in 40 , we had a range day every month for the 10 years I did this and I never seen or read/heard of any our our units across the country having a kaboom ....
but I have read about it on the internet and reloading forms but never personally seen it
 
The issue is summarized nicely on the Wikipedia website: https://en.wikipedia.org/wiki/.40_S&W#Case_failure_reports

The 40 is a high pressure round with a SAAMI max pressure of 35,000 pis. But so is the 9mm Luger (35,000 psi), 38 Super (36,500 psi) 357 SIG (40,000 psi) and 10mm 37,500 psi.

Even a low pressure round like the 45 Auto (21,000 psi) will blow cases if they are not sufficiently supported, or the brass is bad, etc, just like any semi-auto case.

Case strength must always be matched to peak chamber pressure and chamber support for the case in order to be safe. If any of these don't meet standards, you're in trouble. Fortunately, this rarely happens.
 
Among currently-popular cartridges designed for full/duty-sized pistols, the 45ACP is the outlier for being a somewhat low pressure cartridge. All guns for all cartridges need to be designed to provide adequate support, and brass needs to be designed and made up to the task of the given cartridge as well, but there is absolutely no need for any sort of exotic locking mechanism for holding up to 40 or 10mm or 38 super or 9mm +P level pressures.
 
Status
Not open for further replies.
Back
Top