David the Gnome
New member
Probably because it was never chambered with a barrel long enough to show any kind of accuracy. 
Inherently accurate calibers
- Thread starter Ben
- Start date
45_Shooter
New member
The heavier weight bullets necessarily reduce case capacity in order to satisfy OAL constraints, as I'm sure you know. When case capacity goes down the cartridge becomes more pressure sensitive to smaller changes as you also seem to agree. A certain amount of bullet setback from repeated chambering might raise pressure slightly in a 155 grain loading because the effective capacity is more, but will likely increase pressure more for the same amount of setback in the 180 grain load since effective case capacity is less. That's all I was trying to say.
If you look at the develoment of the .40 S&W from it's start as a cut down 10mm, the appropriately designed beefy case web of the 10mm had to be reamed out in order to fit the heavier 180 grain bullets in the shorter OAL .40 casing; this design was necessarily transferred to the eventual production .40 S&W cartridge case and therefore removed some of the original safety margin that had been built into the 10mm case. I believe this along with the above factors are why we see more case head ruptures in this caliber.
OK, you got me here and I should have chosen my words more carefully. I believe one of the major common denominators for most target loadings is the fact that they are driven subsonically to avoid ballistic destabilization from dropping below the sound barrier, but retain enough energy to initially stabilize the projectile, cycle automatic actions, and/or meet power factor. In many smaller calibers this requires heavier bullets to accomplish; in a .45 it pretty much means most loads and since lighter bullets recoil less, they are chosen.
What I believe this means to the .40 S&W is that the heavier 180 grain will be the most likely to accomplish this; although it does look like 165 gr.'s might be able to be acceptable with careful load selection. I don't load for .40's so I can't speak to actual experience here.
I enjoy a spirited and civilized discussion; I take no offense to anything you've posted and appreciate the input of obviously knowledgeable individuals such as yourself.
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The SAAMI pressure specifications for the 9mm and the .40 S&W are identical. Both are listed as 35,000psi.
The .40S&W was not designed for combat, it was designed specifically to match the specifications of the FBI loading of the 10mm--an LE, not a military, application.
A bit of research on the web will turn up .40S&W blowups in other pistols. One factor that's commonly overlooked is that Glock was first to market with a .40 S&W pistol (they even beat S&W) and subsequently grabbed a large share of the .40S&W LE market. That means that at a time when other manufacturers weren't selling many.40 S&W pistols, Glock was selling LOTS of them. Why is that important? Two reasons.
1. The effect of setback on the .40 S&W was not understood yet. As little as 0.1" of setback (or initially seating the bullet too deep by that amount) with a 180gr bullet can double the discharge pressure. Reloaders, used to the much lower pressure and much more forgiving .45ACP found out the hard way about setback and the necessity of really paying close attention to OAL. Combine that with the common practice in LE of rechambering duty ammunition after daily inspections, Glock's larger chambers and the issues with Glock rifling and lead, and you have several pitfalls to avoid--pitfalls that most people didn't even realize existed.
2. At least one major manufacturer (Federal) had to redesign their original .40S&W cases because they were initially too weak.
caliber/cartridge
OK but, my error....It wasn't my intention to ask about "rounds"/cartridges. I should have written out my question as "6mm bullet". I was asking about bullets and calibers. Is there a pistol equivalent, in terms of reliable accuracy, of the 6mm bullet that the BR rifle guys use so well?
I've noticed, in this thread and another about favorite rifle calibers, that most responses are about a particular cartridge as opposed to a caliber. Why is that, I wonder?
Pete
OK but, my error....It wasn't my intention to ask about "rounds"/cartridges. I should have written out my question as "6mm bullet". I was asking about bullets and calibers. Is there a pistol equivalent, in terms of reliable accuracy, of the 6mm bullet that the BR rifle guys use so well?
I've noticed, in this thread and another about favorite rifle calibers, that most responses are about a particular cartridge as opposed to a caliber. Why is that, I wonder?
Pete
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John K. Sa
Pressure levels for 9x19 and .40 S&W: I was taking information from the pressure levels shown in the Lyman Reloading manual. (I was thinking the pressure levels were the same, but couldn't find a citation in any of my reference books here at the house. Thanks. I'll remember the SAAMI website in the future.) Working at the same pressure levels, the smaller capacity of the 9x19 still makes the round more sensitive to minor changes. There's no way around that.
Been searching the web for .40 S&W catastrophic failures.
The Gun Zone (I can't find a date) discusses the failures in .40 S&W Glock pistols. They mention Federal ammunition company redesigned the web structure in their cases, seemingly in response to Glock pistols only. As it happens, the cases weren't too weak for regular guns, just Glocks.
The Browning Hi-Powers Owner's forum has a posting by 'bhp9' who cites an article "Several years ago in “Combat Handguns Magazine…” recording a "…Ruger auto cast gun in 40 S&W blew up…" That's one other than Glock. No details about ammunition, factory or handloads. (Actually the article was more about cast frames than the .40 S&W.)
Covering several pages of search results (".40 S&W blow ups") I find only the one reference to Rugers, the rest cite Glocks. If you care to cite some other examples of firearms other than Glocks blowing up (other than the one I mentioned), please feel free. In the meantime, I'll stand by the information I already have: It is primarily and overwhelmingly a Glock problem.
Regarding bullet set back: Yes, in a pistol sized case, displacing .1" of case volume is a substantial change and a substantial alteration of pressure levels. I don't have the time (or interest) to calculate the volume for a .40 S&W case, or the difference in volume for a .1" deeper bullet. However, as the internal case capacity of the 9x19 cartridge is smaller, it follows the percentage loss of volume would be greater for a .1" setback for a 9x19 round. So; why don't 9x19 pistols blow up more if the same rounds are loaded over and over? How is it 9x19 rounds are immune to set back?
The .40 S&W was not designed for combat? Sir, the .40 S&W round and the .45 ACP round were both designed for close order, reactive use against a hostile human being. In this sense – which is that I was using – the two purposes are the same. If you want to claim the .40 S&W was not made for a military weapon, you are correct; but that, sir, is a pointless and irrelevant distinction. In any event, the .40 S&W was not designed or conceived as a target, plinking or hunting round. It was made for self-defense (not offense) use against hostile human beings. Just exactly like the .45 ACP.
Pressure levels for 9x19 and .40 S&W: I was taking information from the pressure levels shown in the Lyman Reloading manual. (I was thinking the pressure levels were the same, but couldn't find a citation in any of my reference books here at the house. Thanks. I'll remember the SAAMI website in the future.) Working at the same pressure levels, the smaller capacity of the 9x19 still makes the round more sensitive to minor changes. There's no way around that.
Been searching the web for .40 S&W catastrophic failures.
The Gun Zone (I can't find a date) discusses the failures in .40 S&W Glock pistols. They mention Federal ammunition company redesigned the web structure in their cases, seemingly in response to Glock pistols only. As it happens, the cases weren't too weak for regular guns, just Glocks.
The Browning Hi-Powers Owner's forum has a posting by 'bhp9' who cites an article "Several years ago in “Combat Handguns Magazine…” recording a "…Ruger auto cast gun in 40 S&W blew up…" That's one other than Glock. No details about ammunition, factory or handloads. (Actually the article was more about cast frames than the .40 S&W.)
Covering several pages of search results (".40 S&W blow ups") I find only the one reference to Rugers, the rest cite Glocks. If you care to cite some other examples of firearms other than Glocks blowing up (other than the one I mentioned), please feel free. In the meantime, I'll stand by the information I already have: It is primarily and overwhelmingly a Glock problem.
Regarding bullet set back: Yes, in a pistol sized case, displacing .1" of case volume is a substantial change and a substantial alteration of pressure levels. I don't have the time (or interest) to calculate the volume for a .40 S&W case, or the difference in volume for a .1" deeper bullet. However, as the internal case capacity of the 9x19 cartridge is smaller, it follows the percentage loss of volume would be greater for a .1" setback for a 9x19 round. So; why don't 9x19 pistols blow up more if the same rounds are loaded over and over? How is it 9x19 rounds are immune to set back?
The .40 S&W was not designed for combat? Sir, the .40 S&W round and the .45 ACP round were both designed for close order, reactive use against a hostile human being. In this sense – which is that I was using – the two purposes are the same. If you want to claim the .40 S&W was not made for a military weapon, you are correct; but that, sir, is a pointless and irrelevant distinction. In any event, the .40 S&W was not designed or conceived as a target, plinking or hunting round. It was made for self-defense (not offense) use against hostile human beings. Just exactly like the .45 ACP.
Dark Gael
Okay. I understand.
Not to my knowledge, as such. I do know the .32 S&W Long is considered a very accurate round in Europe; they even make a couple autopistols for it, much like the .38 Special in the M52 or the Gold Cup.
I think - and this is not much more than supposition - the .32 (312) caliber bullets being smaller in diameter than .358 or .452 bullets would be easier to hold to tolerances and maintain radial symmetry. That's the theory about the .223 and .243 bullets, anyway. Given the difference in accuracy levels between handguns and rifles, I'm not sure it makes much difference.
I have to say I like your train of thought. You seem to be inquisitive and desiring to 'explore' different approaches to well established questions and answers. So did J. M. Browning, David Williams and Dr. Einstein.
Okay. I understand.
Not to my knowledge, as such. I do know the .32 S&W Long is considered a very accurate round in Europe; they even make a couple autopistols for it, much like the .38 Special in the M52 or the Gold Cup.
I think - and this is not much more than supposition - the .32 (312) caliber bullets being smaller in diameter than .358 or .452 bullets would be easier to hold to tolerances and maintain radial symmetry. That's the theory about the .223 and .243 bullets, anyway. Given the difference in accuracy levels between handguns and rifles, I'm not sure it makes much difference.
I have to say I like your train of thought. You seem to be inquisitive and desiring to 'explore' different approaches to well established questions and answers. So did J. M. Browning, David Williams and Dr. Einstein.
45_Shooter
New member
One thing I might add to help explain this is that 9x19 is mainly loaded to minor power factor, which means that dedicated target loads can actually be reduced in charge over factory loads, which drops operating pressure down and makes the round more tolerant than it might otherwise be with it's small volume.
The .40 is more typically loaded heavier and used to make major, which means that pressure levels are going to run around maximum and heavier bullets are likely to be used, which can make things very sensitive as already discussed.
Also, the 9mm cartridge itself is designed to safely operate considerably beyond 35k PSI; 9mm NATO loadings reportedly run at 40k+ PSI, so there must be a significant safety margin in the pressure/volume equation since we can assume that current USGI issue ammo is not running on the ragged edge of rapid pressure rise from bullet setback.
.40 S&W is never loaded any higher than 35k PSI, and as stated, it is known to be catastrophically sensitive to bullet setback in certain loadings. This indicates to me that the .40 S&W is likely more susceptible to pressure spikes in it's standard loading than 9mm is, which would make the 9mm a more consistently stable round for target shooting.
The article in the 2009 Hodgdons Reloading Annual I was referring to was by Charles E. Petty and showcasing the new Winchester AutoComp powder. I'll post up the direct quote from it when I get a chance.
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I think if you re-read that article you'll see that the author says that the Federal cases were the problem but that the Glock chambers were a contributory issue.
"The causality in this instance appears to have been the Federal nickel-plated cartridge case, and is not an unknown happenstance with this particular manufacturer."
"...the primary problem resided in the Federal case, although the unsupported Glock chamber was almost certainly contributory."
I can tell you that there were other guns (not just Glocks) blown up by the Federal .40S&W before they redesigned the cases--you found one and here's another related to the Federal brass issue.
http://shootersforum.com/showthread.htm?p=120906
The Gun Zone notes that Glocks are not the only gun subject to .40S&W blowups.
http://www.thegunzone.com/glock/glock-kb-faq.html#do
One was designed for combat, the other for LE. While the uses are in some ways similar, there are other ways in which they are quite different. Careful testing to verify performance with non-expanding ammunition would be one example of something that would be critical for the development of a combat round but which would be of little import in the development of an LE cartridge.
Arguments aside, even if there were no difference at all between the design process or goals, the fact would still remain that the round was developed for LE, not for combat because that's how it happened.
Good questions. If you could somehow spare the "time or the interest" you could almost certainly find some answers--45_Shooter has provided some of them.
.32 WC
It is a very accurate round in the International CF game. All of that shooting, though, is done at 25 meters (except for the Free Pistol). The problem with the .32 WC in NRA Conventional Outdoor matches, despite its evidently inherent accuracy, is the 50 yard precision stage. Evidently some shooters experience a fall off in accuracy with that little cylinder; it runs out of steam and destabilizes at the longer distance (more a problem with the load, perhaps, than the inherent accuracy of the bullet).
All in all, though, I'm inclined to go with the wadcutter in general as the most inherently accurate pistol bullet. It'd be interesting to see how a jacketed WC bullet would shoot from a .45 or one of the .40s (and to get them to feed reliably).
Pete
True.
It is a very accurate round in the International CF game. All of that shooting, though, is done at 25 meters (except for the Free Pistol). The problem with the .32 WC in NRA Conventional Outdoor matches, despite its evidently inherent accuracy, is the 50 yard precision stage. Evidently some shooters experience a fall off in accuracy with that little cylinder; it runs out of steam and destabilizes at the longer distance (more a problem with the load, perhaps, than the inherent accuracy of the bullet).
All in all, though, I'm inclined to go with the wadcutter in general as the most inherently accurate pistol bullet. It'd be interesting to see how a jacketed WC bullet would shoot from a .45 or one of the .40s (and to get them to feed reliably).
Pete
45 Shooter
From "TM 43-0001-27 Army Ammunition Data Sheets Small Caliber Ammunition FSC 1305"
Cartridge, 9mm, ball is authorized for modified M3 submachine guns or commercial weapons; it is not authorized for M9 pistols. Velocity is listed at 1125 +/- 90 fps with 115 grain bullet. Pressure is listed at average 38,500, maximum 43,000. So the Army deems the standard pressure for this is 38.5K; that's the target range. The maximum is the upper limits of the safety zone.
Cartridge, 9mm, ball, NATO M882 is for the M9 pistol. It fires a 112 grain bullet at 1263 fps +/- 5 at an average (target) pressure of 31,175 psi, maximum 36,250.
Allow me to add here I know of no other psi listings showing an accuracy level closer than +/- 500 psi. The very precise figures here imply a calculated rather than measured pressure value.
Cartridge, 9mm High Pressure Test, M905 is the proof load for the M9 pistol. No bullet weight is listed, the velocity is listed as NA and the pressure is shown as 50,000 psi.
As reported elsewhere, the SAAMI standard for 9x19 ammunition is 35,000 psi, the same as .40 S&W. (Typically, military ammo is loaded just a little on the light side, so it doesn't beat up weapons and fail in dire times. Not for economy, but for reliability.)
So no, 9mm NATO rounds do not run at 40k plus. I say this in the knowledge that all NATO designated ammunition is loaded to the same standards in all NATO countries. The idea is to insure all ammunition will interchange at need.
Ah, I think I'm beginning to see light. The title of this thread was "Inherently Accurate Cartridges"; I've been proceeding on the subject of extreme accuracy, such as that required in Bullseye or International precision type matches. You're talking about IPSC or USPSA type shooting. That sort of thing does not require the same level of accuracy, but does require higher velocities and energy levels. We are somewhat discussing apples and oranges.
Correct without demurrer. Running any cartridge at top level pressure ranges makes any minor difference in much anything (bullet structure, primer, type of case, powder charge, temperature, seating depth) cause a greater change in pressure than the same round at lower pressure ranges.
Do What? Where did this information derive?
From "TM 43-0001-27 Army Ammunition Data Sheets Small Caliber Ammunition FSC 1305"
Cartridge, 9mm, ball is authorized for modified M3 submachine guns or commercial weapons; it is not authorized for M9 pistols. Velocity is listed at 1125 +/- 90 fps with 115 grain bullet. Pressure is listed at average 38,500, maximum 43,000. So the Army deems the standard pressure for this is 38.5K; that's the target range. The maximum is the upper limits of the safety zone.
Cartridge, 9mm, ball, NATO M882 is for the M9 pistol. It fires a 112 grain bullet at 1263 fps +/- 5 at an average (target) pressure of 31,175 psi, maximum 36,250.
Allow me to add here I know of no other psi listings showing an accuracy level closer than +/- 500 psi. The very precise figures here imply a calculated rather than measured pressure value.
Cartridge, 9mm High Pressure Test, M905 is the proof load for the M9 pistol. No bullet weight is listed, the velocity is listed as NA and the pressure is shown as 50,000 psi.
As reported elsewhere, the SAAMI standard for 9x19 ammunition is 35,000 psi, the same as .40 S&W. (Typically, military ammo is loaded just a little on the light side, so it doesn't beat up weapons and fail in dire times. Not for economy, but for reliability.)
So no, 9mm NATO rounds do not run at 40k plus. I say this in the knowledge that all NATO designated ammunition is loaded to the same standards in all NATO countries. The idea is to insure all ammunition will interchange at need.
Actually, no we can't. U. S. military ammunition is sealed at the bullet (and primer) juncture with a waterproofing compound. Nor is issue ammunition typically chambered and extracted multiple times as a personal or even LE agency ammo might be. (I leave mine loaded and don't mess with it.)
Yes, but not uniquely. All cartridge ammo is sensitive to bullet setback to some degree or other. The (percentage) amount of pressure rise is proportional to the percentage change of chamber volume. A .1 inch set back in a 9x19 round is going to reduce the interior volume more than a .1 inch set back in a .40 S&W case. That's not a guess or an opinion, that is physics.
Inferences, while handy and often logical, are not proof. Other than faulty reloading practices (like not resizing the case sufficiently or properly seating the bullet (or overloads), there is no reason the .40 S&W should be any more sensitive to pressure spikes than anything else. And it should be less sensitive than a 9x19. The answer may just be the 9x19 has been developed and researched longer. Also, in reality I know of no serious bullseye shooter who uses a 9x19 caliber pistol for serious shooting, other than the M9 or a commercial equivalent (Beretta 92F) 'tuned up' for shooting the 'Service Pistol Match'. I've never seen one used for the standard three gun match. To be fair, I've never seen a .40 S&W chambered pistol either, but the 9x19 round has been around since 1908 and the 40 only dates from early 1990. This indicates to me the 9x19 is not a serious match round for precision shooting after 101 years and the 40 is still in the 'what is this thing?' stage. Also, in the spirit of total transparency and honesty, S&W does make a new version of the old M52 in 9x19 caliber. It is called the 952 Long Slide. I've never seen one in competition; and only one in a display case – it wasn't a Long Slide.
I'd appreciate that.
SAAMI is the standards organization for U.S. Industry. NATO has it's own set of standards and is not bound by SAAMI conventions.
It is universally accepted that maximum 9mm NATO pressures run above the SAAMI pressure limit for standard pressure 9mm. Conventional wisdom indicates that 9mm NATO pressure limits correspond (very generally) to SAAMI limits for 9mm +P and that conforms well to the range of numbers provided in the data you quote from since 36,250psi would be considered a SAAMI 9mm+P loading.
By the way, the M882 is only one specific 9mm NATO loading. There are others, but they must all conform to a maximum service discharge pressure of no more than 36,550psi, a figure that is firmly in 9mm+P territory.
It's also interesting to note that while the M9 is specifically noted as being unsuitable for use with submachine gun ammunition in your quote (maximum pressure of 43,000psi), that doesn't hold true of all 9mm pistols. At least one popular 9mm pistol is rated for ammunition creating pressures up to 43,500psi. The point being, of course, that the 9mm is commonly loaded and known to function safely over a much wider range of pressures than the .40S&W is.
While this is correct, the original assertion made by 45_Shooter that "the 9mm cartridge itself is designed to safely operate considerably beyond 35k PSI" is completely correct as verified by the data you quoted. 9mm NATO ammunition may not operate at 40Kpsi plus, but you quoted from a source indicating that the army definitely has some 9mm loadings that operate at pressures up to 43Kpsi. The M9 isn't rated for use with ammunition that hot, but the G17 and G19 are, per the January 1992 Glock Armorer's manual.
0.1" of setback in a.40 S&W case will reduce the volume by 0.01257 cubic inches while 0.1" of setback in a 9mm case will reduce the volume by 0.00990 cubic inches. That's 16.5% and 18.9% of the total case capacities of each cartridge, respectively.
BUT, that leaves out an important point. Setback isn't about reducing the TOTAL case capacity, it's about reducing the "as loaded" case capacity. As loaded, the bullet takes up a large amount of the total case capacity.
The key is that the setback sensitivity of the .40S&W is related to the 180gr bullet loadings, not to the cartridge in general. Given that autopistol rounds must conform to an OAL specification, heavy (long) bullets must be seated deeper into the cases. That reduces the effective interior volume of the case (as loaded) which means, in turn, that additional reductions by setback to the 180gr bullet loadings actually constitute larger relative reductions in volume than one might expect. It's not so much about the gross amount of reduction in volume as it is about the reduction in volume due to setback vs the initial (as loaded) volume.
So, for an extreme example, take a cylinder with an inside diameter of .40" and a second cylinder with a inside diameter of .355". Now insert a rod of inside diameter into each. Insert the .40" rod into its cylinder so that it's 0.1" from the bottom of cylinder. Now insert the .355" rod into its cylinder so that it's 0.5" from the bottom of the cylinder. Finally, push both rods into the cylinder an additional 0.1" (the same amount). The 0.355" rod, by moving 0.1" deeper into the cylinder has reduced the remaining empty volume of the case by 20%, but the .40" rod has reduced the remaining empty volume of it's cylinder by 100%. In this example, the same amount of setback (0.1") obviously produced a much larger relative reduction of case volume in the .40S&W than in the 9mm.
So it's not just about the empty case volume, it's about loaded case volume--it's specifically about how much room is left in the case after you put a bullet in there and about how much of that room is lost if the bullet gets pushed in too far.
The initial loading (and the most popular for some time thereafter) was the 180gr loading because it duplicated the FBI 10mm loading that the .40S&W was developed to duplicate, and it was this loading that seems to be involved in most of the "incidents".
The 180gr loading of the .40S&W is pretty unique in it's extreme sensitivity to bullet setback. As you point out, all cartridge ammo is sensitive to some degree or another, but not much of it is sensitive to the degree that the 180gr .40S&W is. It's possible that the .45GAP in heavy bullet loadings could be similarly sensitive, but I've not seen any figures speaking to that speculation.
It's more correct to state opinions along the lines of of: "I see no reason...", "I know of no reason...", or "I don't believe there is a reason..." instead of stating them as if they are fact, e.g. "There is no reason...".
Well, hoo-ray, thanks and a tip of the hat.
It is said that if you want to learn something new, read an old book.
While I did not re-read anything by Kephart since making my post to this thread, I recall that he broke down his comments by caliber (diameter) of the cartridge and then making statements about the length of the bullet (in calibers, if you follow me) for the accuracy of the bullet. But while he was interested in such things, it was only for practical purposes. He was no engineer. In fact, he was a librarian turned writer. He was interested in the subject of accuracy, or more specifically, the practical accuracy of rifles in the woods (How to shoot in the woods!) rather than the accuracy of a rifle on the range. The differences are huge, though not unreleated.
He was apparently familiar with the popular forms of target shooting of the day and had a certain appreciation of them. However, he was brought up short one day when showing off a match in progress to a friend. The friend commented that except for the smoke and the noise, it could be a ladies' game. Or words to that effect.
It is said that if you want to learn something new, read an old book.
While I did not re-read anything by Kephart since making my post to this thread, I recall that he broke down his comments by caliber (diameter) of the cartridge and then making statements about the length of the bullet (in calibers, if you follow me) for the accuracy of the bullet. But while he was interested in such things, it was only for practical purposes. He was no engineer. In fact, he was a librarian turned writer. He was interested in the subject of accuracy, or more specifically, the practical accuracy of rifles in the woods (How to shoot in the woods!) rather than the accuracy of a rifle on the range. The differences are huge, though not unreleated.
He was apparently familiar with the popular forms of target shooting of the day and had a certain appreciation of them. However, he was brought up short one day when showing off a match in progress to a friend. The friend commented that except for the smoke and the noise, it could be a ladies' game. Or words to that effect.
I did not read all of the posts so someone else may have stated basically the same thing better.
I believe that any cartridge has the potential to be just as accurate as any other. An earlier post noted that the 40 was usually less accurate than 45 or 9mm. I have observed the same thing, but gun and ammo makers have had over 100 years to figure out just how to make the guns and ammo to get the best performance. Both rounds have been used in the past in competition. The 40 is a more recent round and almost all of the development for this round has been focused on terminal performance and much less on accuracy. I see no reason it cannot be just as accurate if someone is willing to work out all of the details to make it so.
I believe that any cartridge has the potential to be just as accurate as any other. An earlier post noted that the 40 was usually less accurate than 45 or 9mm. I have observed the same thing, but gun and ammo makers have had over 100 years to figure out just how to make the guns and ammo to get the best performance. Both rounds have been used in the past in competition. The 40 is a more recent round and almost all of the development for this round has been focused on terminal performance and much less on accuracy. I see no reason it cannot be just as accurate if someone is willing to work out all of the details to make it so.
45_Shooter
New member
Here you go:
Hodgdons 2009 Annual Reloading Manual:
"All-New AutoComp" by Charles E. Petty
p50 ("Crunching The Numbers")
"Over my years of shooting all the cartridges tested here, I've come to some prety strong personal opinions about them. The absoute accuracy champs are the 9mm Luger and .45 ACP. When power factors were a big deal in IPSC, the .38 Super was the way to go, and the .40 S&W is arguably the best law enforcement cartridge ever. Sadly the small case with it's spiky pressures makes it something of an accuracy problem child, and I have yet to find a load that speaks to me in terms of accuracy."
Edit: JohnKSA; thanks for picking up my fumble! I was under the impression that 9x19 NATO ran a good bit hotter than standard 9mm Luger +P, I probably should have checked my manuals. At any rate the subgun ammo saved my butt from too much embarassment as it proves the original point anyway.
I highly doubt that USGI ammo isn't designed with a large safety margin in the pressure dept to accomodate unexpected bullet setback, but I don't have any hard facts to back it up. Everything else in the military is designed to have multiple layers of safety designed into it so I would assume this to be the case for something as critical as ammunition.
Besides, the fact the 9mm casing can safely operate at the 43k PSI figure you quote (23% more than the max figure seen in the .40) should be evidence enough that the 9mm is inherently more stable and unlikely to be as pressure effected by things such as bullet setback.
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