60,000psi 500 data

[simplicity]

I just wanna say I'm new to the site and it is a great site. Can someone please tell me why no one is loading the 500 smith to it's psi rating? It's a 60,000psi cartridge, why doesn't anyone load it to that? If anyone knows of a place where I can find the data i'm seeking it would be very thankful.

[S.B.]

I just wanna say I'm new to the site and it is a great site. Can someone please tell me why no one is loading the 500 smith to it's psi rating? It's a 60,000psi cartridge, why doesn't anyone load it to that? If anyone knows of a place where I can find the data i'm seeking it would be very thankful.

Where did you get you figures from?

[simplicity]

shooting times did a big article about the cartridge to clear up all the misconseptions about it. They stated that it was a 60,000psi cartridge. When the cartridge first come out every ammo manufacurer only loaded it to 50,000. Whetther to tend torwards shooters hands or to keep the recoil down enough so poeple would buy them I don't know. The article also said that Smith n Wesson has also tested their 500 cylinders to 120,000psi. The Hogdon site is where I find most of my data and they only load the 500 to 50,000psi. I have the magisine at my work I'll get the month and page for you to find and read.

[Prof. Fuller Bullspit]

I suspect that commercial loaders don't load to the rated maximum pressure because of the variance that can occur in loads. It's called a safety margin.

Looking at most cartridges, that last bit of pressure doesn't net you much in the way of performance anyway.

[simplicity]

10,000psi wouldn't note any difference?  I think it would look at the difference between the 44 mag and 454 casull 15,000psi difference there and granted the 454 on the avereage is 8 grain of powder more. My 44 loads shoot a 300 grainer at 1300fps out of a 7.5 barrel,and my 454 loads a300 grainer at 1750fps that to me is a difference. granted it is just a comparisent. I'm not looking to find that there is a major difference between 50 and 60 I just wanna see what it's full potential can be. Another one to look at is to compare the 445 super mag to the 454 pretty much same case capacity different pressures yet the 454 is still 250 fps faster then the 445. Like I said I know there isn't going to be much difference, but I do beleive that 10,000psi will make a difference.

[New Hampshire]

You cant compare pressures between two different cartridges as an example because of too many variables.  What it comes down to is something called the law of diminishing returns.  Its when pressures, velocities and muzzelflash reach a point where adding more and more powder exponentially decreases preformance increases.  So while it MAY seem like a lot, an extra 10,000 psi at the already high pressures probably aint gonna get you much except more pain in the hands.
Brian M.

[Redhawk1]

A good comparison would be the .38 special and the 357MAG. The cases are not that much different in length, but the 357 pressure is a lot more than the .38. Every round is unique. I personally do not believe in pushing the pressures to the max. IMO it is just asking for trouble.

[Prof. Fuller Bullspit]

These data are from the Hogdon website:

http://www.hodgdon.com/data/pistol/454casul.php

I offer this as an example of how a bit more pressure might not give that much extra terminal performance. I am ignoring all of the many variables that go into this equation in doing so including the fact that these two loads use different powders. Sorry about that! Please note that these data are given in Copper Units (CUP) which correlates with but isn't equal to Pounds Per Square Inch (PSI). In other words, a 10,000 unit difference in CUP is very close to a 10,000 unit difference in PSI.


454 CASULL
CASE: FREEDOM ARMS
BBL: 9.375"
PR: WINCHESTER SR

260 GR. FA JFP

---H110 -- 36.0 -- 1954 -- 51,600 CUP
LIL'GUN -- 35.5 -- 1895 -- 37,900 CUP

Here we see two loads. The lower pressure load is 13,700 CUP less than the higher pressure load.  Yet the lower pressure load is only 59 FPS less.

This is what I meant by my statement that you might not net much performance from that last bit of pressure.

[Barstooler]

The March issue of Shooting Times has a good article about the new 460 S&W Mag prototype based on the X-Frame.  It discusses the modifications necessary to the hardened-steel firing pin bushing in the bolster face of the frame to support the entire case head of the cartridge to load it to 65,000 psi.  

If you note how the bolster face of the X-Frame for the 500 S&W is no where near that (e.g., it leaves a certain percentage of the 500 case head unsupported), you might not want to load the 500 S&W to within 5,000 psi of the major modificationthat S&W did to produce the 460 prototype.

[simplicity]

The article I was reffering to where I got the info. I was talking about was the October issue of shooting tims on page 41. I know the comparisons I gave were just that comparisons, I'm just trying to get accrossed why I think it would make a difference and yes the 38/357 is another good exsample. As far as the comparison of the h110 and the lil'gun (I've used both quite prefusly) can't really be taken truly into effect. Reason I'm saying this is the reason why they started using lil'gun in the first place mainly was to get the same performance as other powders without the pressures. From my exsperience though with lil'gun if you use to much it is a instnt pressure through the roof so to speak kinda unlike h110 where it is more of a constant gain without huge spikes.
The major changes to the XVR X-frame  was mostly to being able to eject the spent cases hence the reason for machining the cylinder to wrap around the rim as well as the case, to let that take the pressure as well as the the walls of the case. That is what I took from the March issue's article about the 460.