Anyone ever play around with these?
From what I read, all it takes is a quick barrel and recoil spring swap for the 40. The .45 Super only requires a spring change and is basically an ultra hi pressure .45 ACP way beyond ++P using a specially built case by Starline Brass that has an extra thick case head.
The .40 Super is a special hi pressure 45 case that has been necked down to .40 cal and shoots slightly above 357 mag or 10mm power at bore pressures exceeding either 357 or 10mm.
The slight bottle neck is said to improve feeding dramatically.
I'm thinking a minimum of forged steel components for these powerhouses.
Good link here http://www.jrwhipple.com/guns/40super.html
Assuming you're starting with a 1911 in .45 Auto, changing to .40 S&W requires a new slide, because the breechface is cut differently to account for the smaller rim diameter of the .40 S&W case.
He said .40 Super. That seems to be a .45 Auto case necked down to .40.
I would not shoot .45 Super in a 1911 that had only a spring change. Of course, you CAN shoot it that way, but you can shoot it without any modification at all; how many rounds before something breaks?
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I would not shoot .45 Super in a 1911 that had only a spring change. Of
course, you CAN shoot it that way, but you can shoot it without any
modification at all; how many rounds before something breaks?
Just playing the devils advocate here... why would you say that? The 10mm is a whole lot hotter at very much higher pressures and has not seemed to blow up any guns that had no other special components. On the other hand, what modifications would you suggest? I think you have to have some broken components to know what needs to be strengthened. Like I said before, and I agree with you in principle, I would only want to use a forged steel frame and slide and barrel.
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He said .40 Super. That seems to be a .45 Auto case necked down to .40.
Apologies. Reading comprehension is important.
I added this link in a later edit in case you missed it. Pretty good reading. Especially about the design of the special cases.
http://www.jrwhipple.com/guns/40super.html
Doesn't 10mm run at about the same pressure as 9mm or .38 Super? I run a 20# recoil spring in my 10, and an 11# spring in my .38 Super. There must be something other than chamber pressure that matters? I suspect that a 230 grain bullet, launched out of a case that's .45" in diameter, at 1200fps, is a lot harder on the gun than smaller, lighter rounds, even if they operate at the same pressure.
For what it is worth, the guy I talked to at Stormlake Barrels Co. about the .40 super, said that they had sold about a dozen of the .40 Super barrel kits so far in this month of Feburary.
Another way to describe I think would be to say it is a CorBon 400 ( or is is 440?) with a highly beefed up case head and significantly higher pressures.
I really would like to play around with this .40 Super someday but first I really must learn a lot more about how the barrel locks up in the slide lugs and how the different size barrel links affect that.
Also, would want to explore various ways of enhancing the barrel link assembly to be stronger than original. From my limited analysis, it appears to me that area could be a major area of concentrated stress when firing Triple +P type loads ...
I realize there are many including me thinking "who needs it" but this is afterall a conversation forum and this is good fodder for discussion.
The barrel link area shouldn't be getting that much extra stress if your timing is right; it shouldn't be pulling down on the barrel until after the bullet is gone, and the barrel should be stopping on the VIS, not the link.
The increased recoil is going to be borne by the breach face (which starts the slide moving), the recoil spring tunnel (which stops it), the area of the slide directly behind the tunnel (which will tend to flex when the side is suddenly stopped), the recoil spring guide rod flange, and the frame abutment on which the flange sits (both of which are struck by the tunnel at the rear of its travel).
The slide stop pin and frame holes will bear the brunt of the required extra recoil spring.
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The barrel link area shouldn't be getting that much extra stress
Sounds like you have given it some good thought and with a lot better understanding than I have What is the VLS or does VLS stand for ?
Do you think the lug engagement area between the barrel and the slide could be a weak link in a very high recoil situation ? If the lugs sheared off, then what would happen ?
I think those Starline cases designed to handle 50K psi would prevent any blowup and I imagine the next worse thing would be for the barrel coming off the gun and back at the shooter at a high velocity. that or the slide.
I remember that is what happened to the Berretta pistol in the case of broken slides and the Beretta company changed the pistol so that the slide would be captured if it experienced a breakage in the future.
To preface, I'm no expert. There are actual experts who hang out here, though, and I've spent a lot of time reading their stuff.
The VIS is the "Vertical Impact Surface" and it's what the back of the barrel feet hit to stop the barrel's backward movement after it disengages from the slide. If your barrel is being stopped by the link instead of the VIS, your link is going to break even if you shoot powder-puff SWC reloads in NRA bullseye. But if your barrel is stopping there properly, then the link shouldn't have to do much other than pull it out of engagement with the slide, which shouldn't be much harder with hot loads than with weak ones.
I do think that upper lug engagement would be very, very important, because that 50k psi is pushing backwards on the slide and forward on the barrel (through friction with the bullet) at the same time, so the stress there is going to be very high. I forgot that when I made my earlier list of stuff to worry about. You would want generous engagement, 3-lug contact, and the #1 slide lug touching the bottom of the #1 barrel lug recess firmly.
But you'd also have to be quite sure that good lug engagement could disengage properly before the barrel stops, or you'd have quite a problem.
If the lugs sheared off, I don't think you'd get the slide hitting you or anything. The slide is still going to be stopped by the spring tunnel hitting the flange/abutment. The slide would have to break in two to get loose like that, and 1911 slides are beefier than model 92 slides. Bits of barrel lug might go flying backwards, though.
Yes I see what you mean about the lugs. Although everything is important I see now that the lugs on the barrel and slide are not exactly like the lugs on a bolt action in a rifle. The lugs I see exist to get the slide moving and not really take the major recoil force. The VIS handles all that obviously. But I guess the lugs do take all the rear thrust force from the bore pressure. Thanks for pointing that out.
I think the best job in the world would be to work for a weapon mfgr and test these weapons till they broke under extreme conditions. The best I have been able to do is fire some guns from behind a tree with long string. 22 rimfire at that. Learned a lot though :-)
I wouldn't discount the strain on the lugs, even if they aren't actually important in transmitting recoil. As the slide is trying to move backwards (because the case head is pushing on it), the barrel is trying to move forwards (because the bullet, through friction, is pulling on it), so the locking lugs can find themselves taking quite a bit of pressure. That pressure is at least somewhat proportional to the pressure in the barrel, so cranking up the chamber pressure means cranking up the forces on the locking lugs.
The biggest whack of felt recoil to your hand comes from the slide's recoil spring tunnel hitting the guide rod flange (and therefore the frame abutment).
Have you seen the STI animation in the stickies? It is highly enlightening, as are the Tripp videos.
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I added this link in a later edit in case you missed it.
Pretty good reading. Especially about the design of the special cases.
http://www.jrwhipple.com/guns/40super.html
Well, I don't know who the heck Empire is, but they did not bring out the .45 Super. In a WELL built 1911 .45, the only change needed is a VERY heavy recoil spring. Of course, frame & slide should be 1st rate, barrel needs full support. Small radius FPS helps. BIG problem is Super rounds fit and look like standard 45.ACP. And can be loaded into a gun that can't handle 'em.
Which is why .460 Rowland might be a better choice.
As Rob pointed out... the issue isn't pressure. The chamber is obviously capable of handling that. Look at the chamber walls in a Model 29 Smith & Wesson revolver that contain the pressures of the .44 Magnum cartridge... and those walls are much thinner than the 1911's chamber.
The issue is the locking lugs and the slide itself, and how they hold up under the battering of the recoil impulse. Even with all three lugs bearing the brunt of that... they don't have a lot of surface area. The slide is also pretty thin at the breechface, and it has some sharp corners in a critical area adjacent to the breechface. Sharp corners are full of stress risers... which lead to cracks. I've seen slides crack there. When those cracks appear, the slide and barrel separate momentarily when the gun fires. The case backs up to meet the breechface, and the head becomes unsupported... which means kaboom.
The more the gun is stressed with high pressures and recoil forces... the sooner it will fail. If you want to try such ammunition, I advise strongly against using it in a cast slide.
+1 on that. Constant attention is required, every part is expendable. Because the world is full of fools, I will stop talking up those calibers.
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Because the world is full of fools
Yeah. Like was observed by some wise old sage... paraphrased:
"The pressure required to accelerate a 230 grain bullet to a thousand feet per second in 4 inches of rifled barrel is more than sufficient to blow your eyeballs through the back of your head."
If ya want .44 Magnum ballistics... get a .44 Magnum.