.40 caliber changes?

TheProf said:

Q. Did manufacturers reduce the powder amount in 180 grain ammo to accommodate for the larger bullet size?

Click to expand...

I don't really know the answer to any of your questions, but the 180 grain bullet in the .40 S&W is the original bullet weight designed for the round.

I don't know, but since it is the original bullet weight, and if there is a charge weight difference (which I don't know), I'd probably look at it more that the lighter weight bullets can get more powder rather than the 180 grain gets less.

Don't know about webbing in brass but Glock did change barrel.
As to powder charges heavier bullets always require less powder regardless of caliber.

I sense a possible misconception in your posts that perhaps the .40 S&W has a weak case. That is not true. It has a very strong case. It is the same case used in the .357 SIG.

The "Glock ka-booms" were largely caused by a combination of Glock's generous chamber dimensions, the polygonal barrels that don't like a lot of unjacketed lead bullets, and hand loaders using those lead bullets and large powder charges. It also gained notoriety since a "ka-boom" in a polymer framed gun would often crack the frame, while a similar issue in a metal framed gun would usually just crack the grip panels. I don't believe there were many "ka-booms" with factory, jacketed ammo.

When loading ANY cartridge, heavier bullets use smaller powder charges. Part of it is that heavier bullets in the same caliber are LONGER and do take up more powder space. That doesn't mean they are downloaded. I don't load for pistol cartridges, but just as an example when I load 150's in my 308 with Varget 47 gr is a max load. With 165 gr bullets 46 gr is a max load and 45 gr is a max load with 180's. None of those are downloaded, in fact they are all pretty hot loads right at max for the bullet weight

And even at that there are dozens of types of powder. While 45 gr is a max load with 150's with my powder of choice, other powders max loads with the same bullet would vary between 40-51 gr. But the 47 gr of Varget gives me more speed than the loads with 40 and 51 gr powder.

No one has reduced the power of 40 S&W to prevent Kabooms. The 180 gr load was the original loading and if anything todays loads are faster. They may be using a different powder that doesn't spike in pressure as erratically. Some powders will gradually increase speeds in a predictable manner. Others may be perfectly safe at one loading, but just a tiny bit more powder leads to pressure spikes and kabooms. Some powders are very sensitive to temperature. A load at 70 degrees may be perfectly safe. But at 90 degrees could be overloaded. And a gun left in a hot car could easily reach over 140 degrees. Other powders are much less susceptible to temperature changes and wouldn't increase pressure enough to be a problem when hot.

The early Glocks in 40 caliber had a generous chamber meant to improve feeding reliability. That left part of the case unsupported and in rare cases when all of the factors above lined up at the right time led to cartridge cases rupturing. Glock corrected that problem long ago. SOME brass manufacturers may have increased the case strength as well. Can't comment on that for sure.

Starline brass have a reputation of being very strong. Of course this applies only for folks that reload their own ammo.

40SW kaboom were not specifically a Glock issue. Almost all the manufacturers upscaled their 9mm guns. Which cased caused numerous issues.

I believe M&P was the first to reverse this trend making a 40 gun and porting it to 9mm. The rest followed suit.

tarosean said:

40SW kaboom were not specifically a Glock issue. Almost all the manufacturers upscaled their 9mm guns. Which cased caused numerous issues.

I believe M&P was the first to reverse this trend making a 40 gun and porting it to 9mm. The rest followed suit.

Click to expand...

wrong the HK USP 40 and the Sig P229 both came on the market around 93-94 and were the first pistols built from ground up for the 40 S&W

tarosean said:

40SW kaboom were not specifically a Glock issue. Almost all the manufacturers upscaled their 9mm guns. Which cased caused numerous issues.

I believe M&P was the first to reverse this trend making a 40 gun and porting it to 9mm. The rest followed suit.

Click to expand...

Was the M&P specifically designed and engineered with the .40 in mind? Just curious.....I’ve thought about getting g a LEO trade in 40. Glock seems to have the market saturated, but I’d rather have a gun actually *built* for the 40, if that makes sense.

I got a police trade-in M&P and like it a LOT.

Anchorite said:

Was the M&P specifically designed and engineered with the .40 in mind?

Click to expand...

Yes.

Hilton Yam
https://www.military.com/kitup/2013/02/hilton-yam-10-8-performance-glock.html

Same with .40 – the M&P was designed for the .40, with steel chassis for increased rigidity and none of the durability or function issues of the Glock 22. Oddly, the 9mm was shoehorned into the M&P platform rather than the reverse which is true for Glock, and it is therefore the weakest model of the M&P.

Click to expand...

Anchorite said:

Glock seems to have the market saturated, but I’d rather have a gun actually *built* for the 40, if that makes sense.

Click to expand...

Gen 4 + guns were built for the 40.

I think the Steyr M series was also originally designed for the .40 S&W then the 9mm. version was introduced some time after that.

TheProf said:

When firing 180 grain ammo, do you suspect that it has been downloaded in powder amount to accommodate the larger bullet size?

Click to expand...

The only "downloading" that usually occurs is when a specific requirement/spec is requested, like the Winchester Q4369 180 gr., and even then it is generally negligible for the intended purpose.




GR

I've heard many different stories about brass. Some said that the original .40S&W had a thinner web to allow for more powder, some said that the 9mm was actually a stronger case than the .40 due to a thicker web, and some have even claimed that the 10mm was the strongest/thickest of all. I never believed the one about .40 having a thinner web to allow for more powder because it just doesn't make sense. Wouldn't it be safer to use a less bulky powder to get more in the case? Or why didn't S&W and Winchester just shorten the 10mm a bit less to make the .40? Since I wasn't sure about the others, I decided to do a cut-a-way of the three cases. Turns out (with these three examples anyway) that 9mm (Remington) and .40S&W (Win) are virtually identical in web thickness and brass thickness. Now what really surprised me is that the 10mm (Underwood) case has the thinnest web but the brass thickness is only about .0005" thicker than the other two.

JTQ said:

Yes.

Hilton Yam
https://www.military.com/kitup/2013/02/hilton-yam-10-8-performance-glock.html

Click to expand...

Damn good to know. Thanks!

Most 40s that have been designed after the round was developed are designed to be 40s. Many if you look add a little metal to the slide some like the FN FNS are very obvious from external slide dimensions.

TheProf said:

When firing 180 grain ammo, do you suspect that it has been downloaded in powder amount to accommodate the larger bullet size?

Click to expand...

I can't speak to if Federal has reduced the powder charge for 180 grain ammo over time, but I remember reading an article that stated 180 grain .40 is loaded to a lower pressure than 165 or 155 grain .40 because if the bullet is seated a minuscule amount deeper, it drives the pressures over SAAMI spec, so the reduced powder charge helps aid in preventing that.

AFAIK, all ammo makers have done that and have done it since the beginning of the cartridge.

TheProf said:

Q. Is the above historically accurate?

Click to expand...

In regard to KB's, all you need to do is search for images of "Glock case head support." It is very easy to see how it has changed over the years (for the better). No more "pregnant brass" with modern guns.

TheProf said:

Q. Have any other ammo manufacturers also made changes in their case wall or amount of powder in their .40 cartridge?

Click to expand...

This one is difficult to define since different manufacturers can use slightly different brass alloys. It's not like every manufacturer uses the exact same source materials. If we go for the opposite ends of the spectrum, it would be comparing Remington vs Starline. Starline always receives accolades for being the best brass handgun cases, and it is very good, but it is relatively thick and relatively soft. On the other end is Remington handgun brass, which is thin but harder. A prime example of this is brass for 357 Maximum, which is (at least now) typically fired in a single shot firearm and manytimes is handloaded beyond the data published for revolver use. In high pressure loadings, the Remington brass is more desirable since it deforms less at higher pressures. That is an extreme example. In contrast, 40S&W doesn't require any specific brass and it is very doubtful that someone out there has data on the exact year that manufacturer X changed their case wall of caliber Y by dimension Z.

TheProf said:

Q. Did manufacturers reduce the powder amount in 180 grain ammo to accommodate for the larger bullet size? (Versus other .40 weights)

Click to expand...

Nope. The original spec was a 180gr bullet at 980fps, which is easily attainable (with plenty of powder capacity) with medium burn rate powders.
This particular question makes me want to Morpheus meme it with, "What if I told you.... 200gr bullets were available for 40S&W." Now, 200gr bullets look wonky in the case because the heel of the bullet is where the case thickens, making a bulge at that location. However, 200 gr 40S&W offerings are available from manufacturers like Double tap and Buffalo Bore, in addition to handloading options.