.40S&W vs 10mm GLOCK

[Ruger45LC]

Originally Posted by 57K

Well here's an example of Glock's wonderful chamber support: http://thefiringline.com/forums/showthread.php?t=531903 and it occurred with a G21.

Ruger45LC, the point is that anything the .40 S&W can do can be done at much lower pressure in a 10mm case. Most .4005" JHP bullets are designed for .40 S&W velocity level but that doesn't hold true for all of them and the higher velocity that the 10mm is capable of requires an appropriate bullet. You Glock guys kill me with some of your claims: "The last batch I shot was some cheapo 180gr hardcasts through the Gen4 G20 and it grouped an honest 1-1.5" at about 15-20 yds."

What cheapo 180 gr. Hardcast load was that? An honest 1 - 1.5" at ABOUT 15 -20 yards? So your group measurements were accurate while your distance estimation may have been off by 25%?

You guys claiming that there are no leading issues with polygonal bores should really pay attention to sage advice that a polygonally rifled barrel needs to cleaned of lead residue much more frequently than a conventionally rifled barrel. Personally, I think you should shoot all of the cast lead you want to from a polyganol bore, its the advising others to do so that I take exception to.

I seen that thread, but blowouts can and do happen in all guns. I've said it for quite some time that .45 Glocks have the worst case support I've ever seen (and I own 2 of them), but you don't generally see issues due to the typically lower pressures of the .45 ACP. But I've seen it happen with other peoples Glock .45's.

On the subject of .40 vs 10mm and you claiming the 10mm can do it with "much" lower pressure, that as always depends. If your goal is to get a 180gr at 1000 fps, if you use the same powder then yes the 10mm will be lower pressure. But some powders the .40 would be lower pressure, but I'm sure you know that. As for most loads including warmer loads, I would agree that the 10mm would do the same velocity with somewhat less pressure, but not necessarily a lot less.

A quick example is hodgdon longshot using a 180gr XTP. According the hodgdon, the 10mm is faster by about 130 fps, but it's also higher pressure and is using a longer barrel. Cut an inch of barrel off and lower the pressure to the same as the .40 and the 10mm might still be slightly faster, it won't be much faster. In addition, if you dialed it down just a tad bit more it's true the 10mm would be at less pressure with the same velocity as the .40 using longshot, but there won't be a huge difference.

A few .400" JHP bullets can withstand 10mm velocities, but not many, and even then they're fragmenting and/or penetration is suffering as a result. The XTP lineup does pretty well, but they're not perfect for full on 10mm velocity either. Did I mention I was a Glock guy? I can shoot them well, maybe you cannot which is why you act as if it's not possible for a Glock to shoot accurately, let alone with a hardcast.

I mean I've had some hardcasts not shoot so well out of my Glocks, but I've had some that do. The cheapo bullets I was using are from Z-cast bullets, a 180gr round nose design. I say cheapo because they aren't the nicest looking cast bullets I've ever bought, but for backyard shooting who cares right? Since I've shot a lot of poppers at 25yds, I know the target I was shooting was between 15-20yds, but likely closer to the 15yd side of things, which isn't far at all as you know. I was getting my rear sight aligned so I'm not shooting left/right downrange and yes they shot very well.

I never said there were NO leading issues with Glock barrels, sure there is depending on the bullet. If I shoot through one of my KKM barrels I sometimes get leading too. I just keep an extra close eye on it in Glock barrels and if a load is leading it up quickly, I make note of it and make sure I clean the barrel to get the leading out of there. Pretty simple. For a very long time I was strictly against using lead in Glock barrels just for the idea floating around that it was somehow unsafe, yet I broke down and tried and it and guess what, it works just fine.

[Sevens]

My dig at Ruger with regards to 10mm was a fun little jab at you because Bill Ruger vehemently shot down any chance of his guns so chambered. The mass-produced and totally serviceable tupperware tools that you seem completely enamored with (the SR series) could one day be chambered in 10mm since Bill Ruger is *gone.* If he were still here, your favorite line of pistols would still be capped at 10 rounds max capacity.

FWIW, I own seven Rugers and one Glock. Not that it even makes sense to post that, since you will accept -NOTHING- as genuine, truthful or honest. Case in point:

Sevens, I've been at the load bench even longer so I fail to understand how someone of your experience doesn't notice the case-mouth scarring typical of Glock autoloaders. Why do you think that just about every other pistol maker in the world relieves their ejection ports. Check out the gunsmithing videos from API and you'll see that one of their first recommendations is to relieve the ejection port. Nor have you seemingly considered that the triangular scarring can lead to premature case-mouth splits. Reminds me of the old axiom: "when a man claims to have thirty years of experience, but has been doing it wrong for 29, he actually has 1 year of experience."

The only Glock I own is my EDC and I rarely shoot my 1006, my only other 10mm. I do not find other folks 10mm brass where I shoot. So it's all my own brass that I'm running in 10mm and I don't have brass failures of any manner with it. Certainly not mouth splits. This includes even my OLDEST 10mm brass, headstamped "Midway", "3D" and "ELD", the former PMC/El Dorado Cartridge Co. Brass from the early 90's.

More to the point is that I use ridiculous volumes of range pick-up brass in 9mm, .40 and .45, and lots of it is Glock fired. It's obvious as no other handgun on Earth leaves the Glock primer hit. And my 9mm & .40 brass does -NOT- give me failures, either. (I don't find much .45 brass fired from Glock pistols)

My records indicate 9,328 rounds handloaded since Jan 1, 2013.
20,027 was the production from my bench in 2012.
21,041 was the production from my bench in 2011.
My first handloads were .38 Special, Green Dot from a Lee dipper, 158gr Speer swaged LSWC, CCI-500 primers in Federal brass left to me by cops and Feds at the club where I grew up. That was 1989.

I would consider it a personal favor if you would accept all of the above as blatant lies crafted entirely from thin air for the purpose of misleading you.

I laugh at the amount of energy you seem to burn worrying about things like dented brass and other folks' enjoyment of their Glock pistols.

[lightjunkie]

Iam not a handloader yet but I have had a early production gen 3 model G17 since 1997 , with the Clinton ban 10 round magazines which have been long replaced by standard 17 round magazines , the tenifer is wearing off slide.well out of factory rounds fed through including corbon , buffalo bore I have nevr had any brass damaged by the Glock anywhere and a conservative estimate I fed over 6, 000 rounds through it iam not trying to fan the fire just my small limited personal experience.

[Wreck-n-Crew]

The following is written by a retired employee of Ruger. He worked on the development of the P90 and his knowledge on the development of the 40S&W. He was an employee for over 15 years (18 I think).

Some interesting information on the 10mm as well as the 40S&W from someone with professional experience in handgun development in the time when Ruger was considering the development of a 10mm. Turns out that the 10mm demand decline forced Ruger to abandon the development for that reason.

More information from him is available here: http://www.rugerforum.com/phpBB3/viewtopic.php?t=2479
http://rugerforum.net/ruger-pistols/...0-history.html

Ho went by the screen name Coffee Pot and I have no Idea if he is still around.

When the FBI determined the 10mm was too much gun for the average agent to handle, they requested a reduced load, something hotter than a 9mm and about equivalent to the .45 in power. But they wanted to retain the higher capacity that the smaller diameter cartridge would allow with a double column magazine. I don't know who their ammunition supplier was, but in conjunction with S&W they decided that with the reduced load, they no longer needed the long case of the 10mm and could make a .40 cal cartridge with the same OAL as the 9mm and put it on the 9mm platform. However, they wanted to retain the heavier bullet weights. Thus came the truncated cone bullet shape for two reasons. One, the cartridge was quite similar to the 9mm and to make it easier to differentiate between the two cartridges, they didn't want a round nose bullet as with 9mm ball ammo. Also, to keep the heavy bullet weight and yet have sufficient case volume they couldn't have a round nose, it would make the cartridge too long.

The only problem was that the truncated cone shape was difficult to feed. The firearm manufacturers did various things like deepen feed ramps, thus reducing case head support, or making their chambers oversize allowing for excessive case expansion to get their guns to feed. After a short time on the market they started receiving many complaints about case head separation. Many loading manuals added a note to their .40 cal data cautioning the loader to contact the firearm manufacturer to ask if the case head was fully supported. To obtain the required performance, the cases were being pushed to the limit. Then when sombody tried to reload it back to factory specs, they blew case heads. The ammo manufacturers immediately jumped on the issue and redesigned their .40 cal cases. They are all on their 2nd generation cases with a few on their 3rd generation case. Ever wonder why you don't see a +P loading for the .40 like you do for the 9mm or .45? That's why. The normal load is as hot as they can go and retain case integrety. Very few manufacturers operate their ammo at SAAMI spec. They tend to keep the loadings fairly light. Exceptions being the +P, +P+ and military loads.

The bottom line is that the .40 cal was rushed into existance without sufficient development time. The SAAMI spec for the .40 is 35,000 psi as is the 9mm, but with the larger dia cross section and heavier bullets, the impulse was significantly higher as they had to operate at SAAMI spec to get the required performance. The .40 is harder on a gun than the .45 due to its heavy bullets and high operating pressure. The impulse isn't really all that high, but if you break it down mathematically into its force and time factors, the energy is dissipated over a considerably shorter time than the 9mm or .45 thus transferring more of it to the gun. A .45 platform would be more appropriate for the .40 than the 9mm, that is of course, unless the 9mm was beefed up to handle the additional stresses incurred. I'm sure those of you that shoot both the .40 and .45 have noticed that the perceived recoil of the .40 is much snappier than the .45. That is the result of the rapid transfer of impulse energy to the gun.

That's pretty much the story of the .40 S&W as was told to me and also what I've seen during the development of .40 cal pistols. Some of you may have more info or some questions. Please feel free to add your 2 cents worth.

------------------
Coffee Pot

[bitttorrrent]

Wow, long thread.

Finally after getting my inherited father's G20 a new 3rd gen frame, went out and shot it. Very nice. Have never shot a 10mm before.

It is a bit more of a punch, but there is power there. Shot well.

My only problem is that is the only 10mm I have, so I am not reloading that caliber. It will eventually go to my sister as they go up to Canada fishing and could be good for in the woods etc.

I have my G21 he gave me and I like it better.

[Sevens]

Haha, so your sister is going to take a Glock to Canada with her for some fishing?

Please update us with how well THAT goes over at the border.

[Stevie-Ray]

You can put me down as just another of the many that have never had any brass damaged by either of my Glocks, one being a 29. Anybody says that's not possible? I really couldn't give a rat's rear.

[zeke4351]

Here you go. Why does the bottom of this picture keep getting left out? Maybe to make some people look like they know their stuff?

[Beretta686]

I think 10mm is an amazing cartridge that can do most anything. If I could own only one gun, it would be a Glock 20.

But despite how awesome the 10mm is, it's a niche cartridge. Unless you're planning on using is as a woods gun to shoot pigs/deer or engaging targets beyond 50 meters or so, there's really no point in getting a 10mm. It's more expensive, it recoils more, it's harder to find and it doesn't make for great ergonomics for smaller hands.

For most shooters a .40 will work just fine, unless you just really want a 10mm and are willing to accept the issues of feeding one.

[57K]

Well, I really didn't intend to post again in this thread because it is almost pointless. Regardless of known issues, it's inevitable that die hard Glock fans will state that they've never seen any of these issues manifested in their pistols.

In the G21 case blowout thread, I posted what I thought was the likely culprit and the OP seemed to agree. In barrels that don't adequately support the case-head, bulges occur. Many just resize their brass to the point that the bulge is removed, but that does nothing to address the fact that the bulged area has been stressed and weakened. When those cases are reloaded and the previously bulged/stressed area find its way back to the 6 O'clock position over the feed ramp, combined with other factors that exascerbate the problem, like using fast burning powder, case-head ruptures can result.

I seen that thread, but blowouts can and do happen in all guns. I've said it for quite some time that .45 Glocks have the worst case support I've ever seen (and I own 2 of them), but you don't generally see issues due to the typically lower pressures of the .45 ACP. But I've seen it happen with other peoples Glock .45's.

Yes, it's possible with other pistols, but in any other caliber than 9mm where there is better case-head support while the strength of the 9mm's case-head is second to no other autoloading cartridge, case-head blowouts occur more frequently with Glocks, even in 21,000 .45 ACP than it's three closest rivals combined, XD/XDm's, M&Ps or the Ruger SR poly series that fully support the case-head.

Sevens, in another thread in the handloading section, you pointed out that you're mechanical aptitude might be less than typical, so let me give you a mechanical explanation of what you might not comprehend. Polygonal rifling does not "bite" a cast lead bullet as well as square cut conventional rifling, so cast lead bullets can't achieve the same level of bullet seal. Because the seal is not complete, hot gases escape from around the base of a cast lead bullet while the burn temperature of the powder is easily high enough to melt lead. This causes molten lead to affix itself to the bore of a polygonally bored barrel. The longer you shoot them the more likely accuracy will be degraded and with enough build up, the bore becomes resticted in bore diameter which will raise pressure with continued firing of cast lead bullets. This is why guys that know what they're doing will limit the number of rounds that they fire through a polygonal bore, or add an aftermarket barrel that is conventionally rifled. By the same token, since polygonal rifling won't properly seal a cast lead bullet, or stabilize one as well as a jacketed bullet, it isn't reasonable to expect that a polygonal barrel will stabilize a cast lead bullet as well as it will with a jacketed bullet and accuracy with a cast lead bullet rarely matches what can be done with a jacketed bullet where blowby is less of an issue where copper jackets have a good bit higher BHN than cast lead. For you to state that you've worked up a cast lead reload that is equal in accuracy to an FMJ, only points out that you're FMJ handload wasn't very accurate to begin with. Reloaders that achieve a high degree of accuracy shooting cast lead bullets through a glock, are almost always using an aftermarket, conventionally rifled barrel.

While the .45 ACP operates at or under 21,000 PSI per SAAMI spec where 19,900 CUP is the same pressure tested by a different method, that's still enough pressure to not be ignored. Then consider that the 10mm's Max. pressure rating per SAAMI is 37,500 PSI. Do so at your own risk with a Glock, I couldn't care less, but when you present such a practice that might be followed by a newer/less experienced handloader, hopefully, I won't be the only experienced handloader to take exception.

[NWPilgrim]

For decades 1911 pistols had barrels that did not fully support the case head. That was a pretty well trusted design. The original .45ACP cartridge and barrel were designed with this in mind. The G21 not fully supporting is not the first time in history.

[57K]

No it's not, and there are 1911s chambered in 10mm that don't provide adequate support of the case-head, either. A case-head rupture is far likely less to occur with a .45 ACP pistol because of its lower operating pressure, but yet it happens. Also less likely to occur in 9mm pistols because of the strength of it's case-head. The standard pressure rating of the .45 ACP is 21,000 PSI/19,900 CUP. Do you really want to ASSUME a similar safety factor with a 35,000 PSI cartridge like the .40 S&W, or the 10mm's pressure rating at 37,500 PSI with a barrel that doesn't adequately support the case-head?

Case-head ruptures are nothing new, but the term Ka-Boom is mostly a result associated to Glock more than any other pistol in history.

[Oceanbob]

.Case-head ruptures are nothing new, but the term Ka-Boom is mostly a result associated to Glock more than any other pistol in history.

I think we also have to acknowledge that the early problems with Glock .40 have been corrected with improved support on the chamber. Over the years the barrels have changed.

Also Glocks out number most other manufactures and as a result will have more problems reported.

[Dashunde]

Right, while its not the most robust design out there, the high quantity of Glock .40's has revealed every weakness, and the internet has spread every failure repeatedly, blowing it out of proportion.

Perhaps if as many .40 Sigs, HK's and Rugers were sold we'd be hearing about them blowing up more often too.

[Stevie-Ray]

Well, I really didn't intend to post again in this thread because it is almost pointless. Regardless of known issues, it's inevitable that die hard Glock fans will state that they've never seen any of these issues manifested in their pistols.

Oh please. Hmmm....could it be because it's TRUE? Every single Glock out there pummels it's brass into oblivion. Then why do Sevens and I carry them for God's sake, since we both reload for 10mm? Doesn't take a nuclear physicist to figure out that obviously not all of them do. Gee, some of them must be perfectly reliable and gentle on brass. I'm not even a "die hard Glock fan," but a 1911 guy.
I am so sick of hearing this attitude of everybody will deny the obvious so they can justify their purchase without feeling like a fool. I hear that about both my primaries. Well, if they are having the problems you and others speak of and they elect to carry them anyway, they're not just fools, but insane.

What cheapo 180 gr. Hardcast load was that? An honest 1 - 1.5" at ABOUT 15 -20 yards? So your group measurements were accurate while your distance estimation may have been off by 25%?

Strange, but I see a +/-25% estimate on distance and a +/-33% estimate on group size.

[zeke4351]

I like the 10mm but I do not like Tupperware guns in any caliber. Below is my latest edition to go with my 1076 Smith.
I only shoot the full power loads because I own a couple of .40S&W guns if I decide to shoot something weaker. The .40 was developed for the FBI to copy the watered down wuss 10mm load they wound up shooting. The soft shooting 180 grain 10mm load became the .40 S&W which some claims to stand for short and weak. Someone earlier was talking about the Winchester 175 grain 10mm ammo. I shot some of that ammo yesterday and it was the weakest that I shot compared to the other ammo. I had two kinds of Doubletap 10mm with me and it is way stronger than the Winchester. The Winchester is the hottest of the weaker ammo like Armscor or PMC. A lot of people that chrono Doubletap have too weak of a recoil spring in their gun and that let's the slide open too fast to get a good burn of the powder and the speed of the bullet is slower than expected.

[VinnyT]

I love caliber wars...

[RBid]

I'm the dangerous kind of guy, living life on the razor's edge. I shoot the .40 regularly. My first Glock 23 (Gen 3) didn't blow up, so I traded it in on a Gen 4 to roll the dice again. So far, no kabooms. Any day now, internet statistics will kick in, and myself and a few hundred thousand LEOs are going to die bloody kaboom deaths. That's how I like it.

I'm daaaaangerous.

[lightjunkie]

Hahahah lololo

[VinnyT]

I shoot a G22. I like the gun, great for CCW. I'm pretty sure that if I need to defend myself with it, I can. If you like 10mm, fine. Yup, that caliber will also take down a BG.

Not sure why the huge discussion but carry on!

[Xfire68]

@zeke4351

The picture looks like a nuke went off! Handheld Nukes!!!! LOL

Mine is not a CC rig but, I love it!