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Discussion Starter · #1 ·
I've long been intrigued by the .45 Super cartridge which began as cut down .308 cases; allowing higher pressures. The thought occurred to me that the same might be done with the venerable 9mm Luger cartridge; by cutting down 5.56 or .350 Legend cases to 9 X 19 case lengths. The thicker cases would allow higher +P pressures.
 

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That was done over 4 decades ago by a sterling individual known as Jeff Cooper. It was shot from a very carefully built 1911 which started life as a .38 Super. Since it was Col. Cooper's brainchild, it was unofficially dubbed the "9mm Super Cooper". Performance was on par or slightly better than that obtained from a 4" barreled .357 Magnum.
Do some googling on the terms "9x21 mm pistol" and ".356 TSW". If I correctly understand what you're hoping to do, I think it's already been done.
 

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Ged -

Howdy !

Thinking out loud.....

Necking-down the comparatively short 9mm cartridge to make a smaller calibre wildcat would be problematic.
Case capacity redux woud be one by-product of the process, even if a sharp shoulder angle were do-able on the case.

One might operate using the longer 7 X 33 Sako, which is the longest draw that has been taken on 9mm Parabellum
case making machinery. This case features rim diam that is around .016" large than the rim of a .357Legend.

The " Legend " is more or less a .357Max formed using a slightly lengthened. 222 Rem case as the starting point.
Or.... a shortened .223 or .222 Mag case, if you want to look at it that way.

I DK whether you are thinking about an AR application for the imagined wildcat ?
I can say that if you wanted to wildcat on brass that has .44Magnum diameter brass and was rimlesss; you could
form such a wildcat using shortened .35 Remington brass.

So... besides things like calibre and parent brass used for the wildcat; case/ cartridge oal are dimensions TBD.


With regards,
357Mag
 

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Discussion Starter · #6 ·
Hi All,
I'm not surprised that this has been tried before. Back in the 70s I was experimenting with some ++P reloads in 9mm; pushing 115 grain bullets up to 1,400 fps.
I learned two things.
These high pressure loads were really hard on case life. One or two shots then throw the cases away. I had a case blow out down the feed ramp. Cracked a grip but no other damage done.
The other thing I learned is that groove diameters of 9mm barrels vary wildly. I slugged a number of barrels at my gunsmith and found groove diameters from 0.352 in a S&W Model 39 to 0.360 in a Browning Hi-Power.
You're comparatively safe if you develop a hot load in a tight barrel then switch to a gun with a larger groove diameter. The reverse is trouble.
My thoughts on cutting down a 5.56 case to make a 9mm cartridge case was to get a case that is thicker over the feed ramp. I plan to try this if only to see if it's possible to make a 9mm case out of a 5,56 case.
 

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Necking-down the comparatively short 9mm cartridge to make a smaller calibre wildcat would be problematic.
Not what he is wanting to do. He wants to start with a 223 Rem. (or5.56) case and cut it to the length of a 9mm Luger case length. Purpose is to have a 9mm bullet in a case with wall/web thickness greater than standard 9mm Luger to handle higher pressures while preventing case blow outs. Jeff Cooper's Super 9 did that, but to the 38 Super case length, not 9x19.
 

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GED1593,

If this is to go into a 1911, the other route to take is to look at the numerous aftermarket ramped barrels made since Cooper's experiments were done, which don't leave a significant part of the case unsupported. You would find you don't need quite such thick brass with them. If you still want thicker brass, also look at the 9 mm cases made by Maxxtech with an internal step to really thick sides and a narrower powder space formed below the ledge. With a specially made reamer and a drill press, these could be modified to the wall thickness of your choice.
 

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Thicker cases means less capacity which defeats the purpose. ;)
Not always. If thicker cases are used to develop "normal performance/pressure" loads then I agree that nothing much is gained (perhaps greater economy of propellant from reduced charge weights?).
If cases with thicker webs are used to develop loads that significantly exceed the SAAMI spec pressure for that round, then better ballistic performance can likely be obtained, though ultimately at the cost of the firearm.
The 5.8/Unique/124, 125 gr. "whatever" loads that I routinely assemble in "normal" cases for practice, competition, and social work are unlikely to work with the cut-down and reamed .223 cases. FRANKLY, I doubt that the thicker-webbed cases will accommodate so much of a bulky powder. A more dense propellant, whether faster or slower burning, may need to be substituted.
Hodgdon/IMR/Winchester/Western/Whomever's next Powders lists data for the 9x23 Winchester, consisting of propellant, and one projectile (125 gr. JHP). NOT one weight with many configurations, just one. The propellant of choice (according to Winchester) is W231. There are 4 other Winchester propellants which could plausibly be used in the 9x23W, yet WInchester seems less than forthcoming with data for these powders.
I have read that the thicker brass in Winchester brass is present to very near the case mouth, and that projectiles heavier than 125 gr. seat too deeply in the case to avoid bulging. I wonder what Winchester's explanation is for not publishing data for 115 gr. projectiles...
VV and other members of the business likely publish data with other propellants and bullets, so all is not lost. UNFORTUNATELY, a 9(x23)mm pistol round that develops 55,000 p.s.i. JUST seems too good a thing to not try it with cases which will readily seat heavier projectiles up to 147 gr. in weight. If it was tried, and the experimenters experienced case failures or other events well forward of the very thick-webbed case head, THIS is useful information, also. I've never heard nor read of such troubles, but anything is possible.
With some judicious reloading, a "standard" .38 Super case can, with relative ease, launch a 147 gr. TC-PC projectile at slightly more than 1150 f/s from a 5" 1911 originally chambered for the .38 Super. These numbers make "Major" in contests where such things are measured, and approach, but do not exceed SAAMI max for the round. I would expect similar attempts in the 9x23W with the 147 gr. projectiles, to beat the .38 Super numbers by at least 10%, if not 20%. These extra velocities mentioned may be met with a yawn from 9x23W owners who only use these arms in competition, whose only real interest in their reloads is that they always exceed the 165,000 ("Major") PF threshold, and shoot as accurately as possible. Such results might interest Law Enforcement and the civilian pistol wearer in that they would rival the performance of the .357 Magnum 158 gr. rounds, as fired from a 4" barrel, but in a platform holding half-again to twice as many rounds.
Okay, I went far afield on this one, but the main point I wanted to stress that thicker case webs are a waste if the brass is to be loaded to "standard" performance levels. Thicker case webs MAY NOT BE a waste, if the goal to is to use them to work up load data developing a substantial increase in chamber pressure (55,000 p.s.i. for the 9x23 W, vs. ~38,000 p.s.i. for the .38 Super) and, one hopes, significantly greater performance, then experimenting with cut & reamed ,223 rounds MAY take you somewhere. But beef up the test pistol, before you get serious.
 

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In my most humble opinion-- High pressures need better guns. Rotary bolt pistols are big, heavy, clumsy, and hard to carry but they ARE designed to take more pressures.
Hot rodding plastic pistols is not on my entertainment list.
 

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GED1593, If this is to go into a 1911, the other route to take is to look at the numerous aftermarket ramped barrels made since Cooper's experiments were done, which don't leave a significant part of the case unsupported. You would find you don't need quite such thick brass with them. If you still want thicker brass, also look at the 9 mm cases made by Maxxtech with an internal step to really thick sides and a narrower powder space formed below the ledge. With a specially made reamer and a drill press, these could be modified to the wall thickness of your choice.
If readily obtainable for whatever 9mm he plans to use, a fully supported barrel AND thicker case web would seem TO ME like a "belts and suspenders' approach. I rarely have trouble when I can apply that approach.

Just looking at the cross-section of that case makes me wonder what the brass makers hoped to accomplish with such a design. It occurs to me that, if the manufacturers are making 9x19mm for use in pistols AND Sub Machineguns (which, typically, uses pistol-caliber ammo too hot for use in pistols), the lower charge weights required for ammo of either application would save propellant, and may prevent case blow-out in SMGs with the hotter stuff. SMGs GENERALLY lack the rather high precision with which almost any locked breech semi-auto pistol on the market is made these days. The thicker web could also be present as a protection against case blow-out in SMGs using "advanced primer ignition", during which the forward-moving bolt's firing pin hits/ignites the primer just before the bolt hits home and the round is completely chambered.
API appears to require lighter bolts (resulting in less forward-backward movement when firing), and may reduce recoil, as the expanding gasses must overcome the forward momentum of the bolt, then send it backward from where it stopped. All very arcane, I think.
Sorry. NOT trying to jack the thread. Again.
 

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Necking-down the comparatively short 9mm cartridge to make a smaller calibre wildcat would be problematic.
Perhaps not as problematic as you think. If you neck-down a 9mm case to 7.65 mm, you get the .30 Luger, which was the parent case of the 9x19mm. The original .30 Luger case was slightly longer, and .30 Luger cases made from 9mm have almost no case neck. But if those reformed cases get shot a buncha times, there'll be more neck.
 

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There are 4 other Winchester propellants which could plausibly be used in the 9x23W, yet WInchester seems less than forthcoming with data for these powders.
I have read that the thicker brass in Winchester brass is present to very near the case mouth, and that projectiles heavier than 125 gr. seat too deeply in the case to avoid bulging. I wonder what Winchester's explanation is for not publishing data for 115 gr. projectiles...
Olin hasn't had the capability to produce powder in quite a long time now. From a number of conversations I've had with Hodgdon over the last number of years, Olin has been rather lax in providing current pressure data, so Hodgdon begins removing older data. When the royalties begin to dwindle and the complaints begin rolling in, the contract gets brought out and who is responsible for providing what; gets reviewed again and somewhat updated. Rather unfortunate honestly.


In my most humble opinion-- High pressures need better guns. Rotary bolt pistols are big, heavy, clumsy, and hard to carry but they ARE designed to take more pressures.
Hot rodding plastic pistols is not on my entertainment list.
Manufacturers do not publicly publish what pressures and cycles they design their firearms to normally function within. Getting them to publish what they design for, for a catastrophic release event; isn't more likely to happen.
But I would love if you have some actual supporting data PROVING what each gun is designed to contain for catastrophic pressure releases.


Cheers
 

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What throws a wrench into hot-rodding semi-auto handguns is the opening of the action. "Locked breech" still starts to open while the bullet is at some point down the barrel; perhaps having already exited the gun, but perhaps not.

Blowback actions are more of the same. With a blowback action, changing the mass of the bolt/breechblock/whatever (moving parts) is the simplest way to make sure the action stays closed and also where things can go off the rails. SMGs can just add a little mass and keep the action more or less reasonably closed, for the correct amount of time. Adding a lot of mass to the moving parts of a handgun makes it heavier and somewhat defeats the purpose of having a portable arm. SMGs often fire from an open bolt - meaning the movement of the bolt forward both chambers the round AND fires it, once the round stops moving forward. That's another design distinction that inhibits accuracy, but accuracy isn't what an SMG is about.

Moving to another type, gas-operated with a rotary bolt (ie. Desert Eagle) it gets somewhat easier to control and keep locked. Why? The action can't start opening till the bullet passes the gas port. Depending on the design, excess gas pressure could (potentially) be bled off to prevent the action from opening too quickly/violently, too. So yeah a gas operated rotary bolt gun should in theory be able to operate where rifles do, pressurewise, but that's a general statement and not an absolute. Still depends on the surface area of the bolt lugs, etc., etc. But the potential is there, though it adds a bunch of weight and makes the gun less portable, for sure.

Complicating all this is chamber dimensions being altered for feeding. That's why it isn't all that great of a trick to make a revolver run at rifle pressures (see the .454 Casul) because the case is fully supported and pressure has long dropped to zero by the time you hit the ejector rod ;)

I suppose it might be an interesting experiment to take a locked-breech semi auto, make it stay locked during the firing cycle (make it a single shot) and seeing what pressure levels it could take. In all likelihood, the feed ramp cutout will be the first point of failure, but maybe not. That may well depend on the brass construction, whereas in a revolver the case wall thickness is mostly a moot point. I'd go, generally, with a rotary bolt gas operated semi-auto as being the most robust of the semi-auto repeating handgun designs.

Last thought, plastic framed guns are probably more likely to be destroyed by a case head rupture than steel framed guns. It wouldn't be fun in either but I've been standing next to a friend who had an all-steel .40 S&W blow a case head off and it didn't hurt the gun a bit.
 

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Olin hasn't had the capability to produce powder in quite a long time now. From a number of conversations I've had with Hodgdon over the last number of years, Olin has been rather lax in providing current pressure data, so Hodgdon begins removing older data. When the royalties begin to dwindle and the complaints begin rolling in, the contract gets brought out and who is responsible for providing what; gets reviewed again and somewhat updated. Rather unfortunate honestly.
Yes, I remember being told on another thread about Olin/Winchester/Whomever not actually manufacturing propellants anymore (NEW information to me, but not surprising). IF they no longer manufacture the propellants sold under the Winchester label (and if Winchester does not either), then WHO ON THE PLANET does their testing?
Does such work get "farmed out" to whatever "Bill & Ted's Ballistic Testing Lab" is available for and bids lowest on it?
 

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Yes, I remember being told on another thread about Olin/Winchester/Whomever not actually manufacturing propellants anymore (NEW information to me, but not surprising).

Does such work get "farmed out" to whatever "Bill & Ted's Ballistic Testing Lab" is available for and bids lowest on it?
This decade old thread is constantly getting referenced for good reason. 😉
Olin sold it's powder manufacturing capability in 1998, so it shouldn't be New info.

But yes, they simply farm it out.
I know for a fact, they've paid GD for info, Western for info. I've been told, but can't actually prove; that some of it was simply calculated based off very old testing.

Cheers
 

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Blowback actions are more of the same. With a blowback action, changing the mass of the bolt/breechblock/whatever (moving parts) is the simplest way to make sure the action stays closed and also where things can go off the rails. SMGs can just add a little mass and keep the action more or less reasonably closed, for the correct amount of time. Adding a lot of mass to the moving parts of a handgun makes it heavier and somewhat defeats the purpose of having a portable arm. SMGs often fire from an open bolt - meaning the movement of the bolt forward both chambers the round AND fires it, once the round stops moving forward. That's another design distinction that inhibits accuracy, but accuracy isn't what an SMG is about.
The 1st generation SMGs are almost all open-bolt blow back (there MAY have been some obscure exception), in which the round going into the chamber didn't fire until the bolt slammed into the back of the barrel/chamber assembly, and the bolt's firing pin struck the primer. In addition to incremental additions of mass to an already massive bolt in the interest of keeping the bolt closed, alterations in recoil spring rate can also be a major factor. Approximations using Hooke's law and a few assumptions about friction can be surprisingly accurate.
With the advent of the Sterling-Patchett SMG, a modification called Advanced Primer Ignition" (ADI) was incorporated in many old patterns and new patterns. The A.D.I. system modified the bolt/firing pin so that it impacted the cartridge primer just before the case became fully seated in the chamber. The resulting expanding gasses had to not only overcome the resting intertia of the bolt, but the forward momentum of the bolt in its final millimeters on the way to the back of the barrel/chamber assembly. The result was that a less massive bolt was required, which decreased a fair amount of the "bounce around" associated with the bolt traversing its path. It improved accuracy somewhatm though as mentioned, great accuracy is(was) not a major design constraint in SMGs.

Came then, the closed-bolt SMGs, a semi-recent development. The H&K MP5 is probably the most famous example (depending on one's definition of "locked bolt"), and a more recent one is the SiG MPX, which uses a gas-operated rotating bolt (TRULY LOCKED). With closed bolts and suppressors, non-contact and (essentially) silent sentry removal was possible well past 50 meters.
 

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As a 15 year old, I found freight cars full of demilled stuff. Most common were M-3 grease guns. Those bolts surprised me! Considerably different than my 550-1 Rem! Ol Greasy was much more fun to shoot.... at great cost to accuracy and ammo budgets.
 

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The M3A1s were issued with a spare barrel and magazine for 9x19mm. To convert the weapon to fire 9mm, r&r the barrels, pull the bolt out and insert it backwards. Insert loaded 9mm magazine, pull back bolt and rock 'n roll.
 
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