Uberti Schofield in 44-40.

[sharps4590]

Admitting my search skills are severely lacking, I can't find any info on the operating pressure of the Schofield, Uberti or otherwise. I have a pretty decent load but it seems anemic. I'm shooting 5.7 grs. of W-231 under a Lee, 200-205 gr. bullet and both the report and recoil are quite tame. No, I have not chronoed the load yet. I'm assuming the 44-40 being a larger case than the 45 Schofield/S&W/Short Colt...whatever one wants to call it....that the same velocity can be reached in the 44-40 at a lower pressure.

Pressure info or loads that are safe in the Schofield is appreciated!!

[KCSO]

In the top break I hold the pressure to just about 16-18000 cup. About the same as the old B/P rounds. A 200 grain bullet at 900fps in a 7 to 8 inch barrel. This is more due to the more fragile construction of the top break than material weakness. Top breaks do not take to hot rodding. I am currently shooting IMR 4227 in the smokless load and a case full of Swiss 2f in black.

[sharps4590]

Thanks KCSO. I wanted to shoot BP but I've read and been told that as the Uberti Schofield's cylinder was lengthened for the 45 Colt and 44-40 that the "shield" that keeps fouling out of the cylinder pin was removed. That if one shoots BP in them the cylinder quickly becomes difficult to turn and clean up is a king sized pain. Any truth to that?

Regarding the 231 load I suppose I need to get out my chronograph and see where it is then go from there.

May I ask your IMR-4227 charge weight?

[Outpost75]

I load 17.5 grains of IMR4227 with Accurate 43-206H in my 1905 Colt Frontier Six Shooter. 6.5 grains of 231 also shoots well, but is a full-charge load at 900 fps.

[Oyeboten]

In the top break I hold the pressure to just about 16-18000 cup. About the same as the old B/P rounds. A 200 grain bullet at 900fps in a 7 to 8 inch barrel. This is more due to the more fragile construction of the top break than material weakness. Top breaks do not take to hot rodding. I am currently shooting IMR 4227 in the smokless load and a case full of Swiss 2f in black.

What is 16-18000 CUP in "PSI"?

I can not get used to 'CUP' since it relates to nothing anyone could or would ever deal with in any part of the real world for anything...it seems an utterly useless approach for measuring Pressure to me.

[sharps4590]

Makes perfect sense to me. Maybe you aren't old enough? Shooters the real world over related to it for over 100 years, to include the best rifle makers in the world. Does LUP give you the same fits of apoplexy?

Outpost, I was doing some digging in my OLD books and not so old books where I found a couple loads I'm going to try. They did list IMR-4227 also and I think the RCBS manual gave 17.5 as a max load....subject to correction of course.

[Oyeboten]

Makes perfect sense to me. Maybe you aren't old enough? Shooters the real world over related to it for over 100 years, to include the best rifle makers in the world. Does LUP give you the same fits of apoplexy?

Outpost, I was doing some digging in my OLD books and not so old books where I found a couple loads I'm going to try. They did list IMR-4227 also and I think the RCBS manual gave 17.5 as a max load....subject to correction of course.

Okay, well, here is what an honest man would have said -

"For all practical purposes, Cup is .927 of PSI..."

So, there is our answer.

[Outpost75]

Okay, well, here is what an honest man would have said -

"For all practical purposes, Cup is .927 of PSI..."

So, there is our answer.

Not so!

Varies a great deal depending upon location of piston hole vs. transducer.

There is no precise correlation. Every cartridge is different.

[sharps4590]

So I'm a liar? No, that isn't our answer from your supposed "honest man". Outpost is correct, you are wrong. No wonder you can't wrap your head around CUP and probably LUP. Don't worry, there's a lot of children's data out there.

Take it up with Holland & Holland, Jeffery, Westley Richards, Rigby, the London, Birmingham, Suhl and Zella Mehlis, Ferlach and Vienna proof houses, and others....unless you know more than they do.

BTW Outpost, another friend sent me a link to some pressure tested data. I found a pressure tested load for SR-7625, which I have an abundance of. I use that powder in my 44's and 45's so Friday I'm gonna load a few to try.

[Larry Gibson]

Okay, well, here is what an honest man would have said -

"For all practical purposes, Cup is .927 of PSI..."

So, there is our answer.

That would/could be a very dangerous assumption.......

Having measured the psi of thousands of loads and having compared them to published C.U.P. pressure figures I agree with all the ballistic technicians who state emphatically; "there is no correlation between measured psi and measured C.U.P. that can be used for conversion of one to the other."

Only in a specific test of both psi and C.U.P. conducted with the same load at the same time under the same conditions can a direct 'correlation" be found. Then it is only correct for that one load.

Outpost75 is most certainly correct in that "There is no precise correlation. Every cartridge [load] is different."

[Wayne Smith]

You were told exactly right, by lengthening the cylinder Uberti did take out the piece that prevented the BP residue from the central part. Thus you really don't want to use BP in these revolvers.

[Outpost75]

Also, you don't want to load a No.3 or Schofield clone over about 13,000 psi or the revolver will remind you and pop open!

[Savvy Jack]

In the top break I hold the pressure to just about 16-18000 cup. About the same as the old B/P rounds.

Are we talking 44-40 here?

[Savvy Jack]

That would/could be a very dangerous assumption.......

Having measured the psi of thousands of loads and having compared them to published C.U.P. pressure figures I agree with all the ballistic technicians who state emphatically; "there is no correlation between measured psi and measured C.U.P. that can be used for conversion of one to the other."

Only in a specific test of both psi and C.U.P. conducted with the same load at the same time under the same conditions can a direct 'correlation" be found. Then it is only correct for that one load.

Outpost75 is most certainly correct in that "There is no precise correlation. Every cartridge [load] is different."

Absolutely 100% correct!!

However, with the 44-40 we can use a simple formula only as a "comparison" and not hard core data. This can be done mainly since the 44-40 is a low pressure cartridge.

First we have SAAMI's pressure data for both CUP and PSI:
https://saami.org/wp-content/uploads...sting-Copy.pdf
Pages 21 and 33

First, psi is psi but the "method" (i.e Copper Crusher vs Strain Gauge) used can result in different psi results, such as SAAMI has published.


"Max Pressure"
11,000psi is 100% equal to 13,000cup in SAAMI's particular test results as published by SAAMI.

Thus we do the math....

Regarding CUP ratings in manuals, while the correlation between CUP and psi is too poor for reliably converting one unit to the other over a range of chamberings, within a single chambering the conversion by the ratio of the CUP and psi maps within the SAAMI system is going to be close enough for practical work. That is, 11000 psi divided by 13000 CUP is 0.846 psi/CUP for the 44-40, so you can take the CUP numbers in the Lyman Manual and multiply them by 0.846 to get a reasonable expectation of psi. Conversely, dividing psi by that same number will come close to CUP." ~Uncklenick

However, this should not be used to "create loads" but used to compare already published loads.

Since the 44-40 has historical published pressures, we can check to see how close the formula is.....

Using documented load data from loading manuals, "historical publication" and conducting pressure tests with a strain gauge system, I came up with the following;

Also note that my black powder tests varied pending components used, however, original loads show 14,285psi which COULD BE just less than 17,000cup. Later components used and even more modern components used all showed a consistent reduction in comparison with published velocities lowing over the years, as well as pressures created. Eventually pressures tapered off to less than 11,000psi and velocities down to what most folks are familiar with, around 1,250fps from a rifle. Over-all this was reduced from 15,000cup down to 13,000cup for whatever reason.

Never forget that "velocity" does not equate to original black powder pressures. When using faster burning pistol powders, one can far exceed pressures before reaching original velocities.





14 Feb 1917

44 Win. for Model 73' - Service Pressure 13,000 (cup), Proof Pressure 16,500 (cup)
44 W.H.V. for Model 92' - Service Pressure 18,000 (cup), Proof Pressure 23,500 (cup)

By the 1930's the 44 W.H.V. was reported to be 22,000 (cup)

[Walks]

I have experience with only 2 Uberti #3 Schofield Revolvers.
Mine is in .45Colt - 7" bbl
Other .44-40 - 5" bbl

The .45Colt has digested many thousands of my Standard Cowboy load of 230gr TC over 5.0grs of Clays, and several hundred of the STD Lyman max load of #454190 -260gr over 9.0grs of Unique.
Neither load has ever popped open the revolver.
The #454424 over 9.0grs Unique will pop it open about 1 in 5 shots.

The .44-40 belonged to a friend who purchased it in that caliber for black powder shooting. He tried his STD load of a #42798 - 210gr over 30grs of 2F with a Wonder Wad between powder & bullet. This load worked just fine in His Pre-War Colt SAA's, Win 1973 & 1892 and Marlin 1889's. In the Uberti #3 the Revolver would start to tie up after less then 20rds.
For smokeless loads he used the Lyman #427666- 205gr or RCBS 205gr - #44-200-CM over 8.0grs of Unique.
If he used any hotter smokeless load the revolver would pop open. It would also pop open when we tried My light load of 225gr Magma FP over 6.5grs of Unique.
When shooting Winchester Cowboy loads of a 225gr bullet or TEN-X Cowboy loads - 200gr it would also pop open.

He sold it off after about 6 months. I've had mine for 20+yrs.

[sharps4590]

Well...thanks to all of you!! Jack, excellent info. Thanks for taking the time and Walks, thanks for your experience. Wayne, thanks for confirming what I've read. Outpost and Larry, thank you for the explanations of CUP, a method that worked just fine for well over 100 years. Also for its comparison to PSI. I do believe PSI is more relatable for most, especially if they're on the lower side of 50 or so but, if a fella understands the CUP system, it works just fine.

To try today, when it warms up, I have loaded 8 grs. of SR-7625 under Lee's 205 gr. bullet which should be less than 11,000 CUP. My 231 load at 6 grs. still felt mild but, that doesn't mean anything regarding pressure. It didn't shoot bad for the rudimentary sights, even after I worked them over and, the creepy, dragging trigger.

https://www.hodgdonreloading.com/reloading-data-center

[Larry Gibson]

Also keep in mind if comparing psi to C.U.P. that with C.U.P. all you get is the crushing of the copper pellet. measuring that "crush" and then comparing the amount of crush on a tarage table gives and approximation of pressure required to give that amount of crush for that shot. The use of a C.U.P. test fixture is slow and tedious and not many rounds are actually tested per load even though SAAMI suggests a 10 shot test. The crush copper pellet also can only indicate the maximum amount of pressure. Published data almost never indicates the number of shots measured to arrive at that pressure figure.

A piezo-transducer or strain gauge is a completely different form of measurement. While also measuring a secondary effect as does the C.U.P. method they offer a much more complete picture of the entire pressure cycle from ignition to muzzle exit. The use of the piezo-transducer/strain gauge methods are also much quicker to use and provide the data from 10 shot tests much quicker and more reliably. The strain gauge method can also be used on many commercially available firearms which gives an excellent idea of the pressures that occur in common firearms. It is also much less expensive than either a C.U.P. or piezo-transducer test fixture.

[Savvy Jack]

I have been asked a few time about the high end of my results...how can I be sure that the CUP and PSI I have documented is accurate.

Well, as we can see by Lyman's 49th handloading manual, Lyman lists a few high velocity loads in CUP. I simply loaded those up and compared them with the psi results I got. Of course, mine are nowhere near offical...but certainly consistent.

Lyman lists a max load for strong action rifles at 19,000cup. My results were 15,618psi which COULD translate to about 18,500cup. Take into consideration Lyman's safety margin (19,000cup), if any....and that is pretty close.

Many test I made, commercial data seems to have between a 5% and 10% published safety margin....pure speculation.

[sharps4590]

Wow!! What a pleasant surprise with the SR-7625 load! 4 shots under 2 inches with one flyer, (self induced no doubt). Group on target was a bit high but will work near perfect with a 6 o'clock hold. Still a bit left but that's the way it is with this ol revolver.

[Savvy Jack]

Wow!! What a pleasant surprise with the SR-7625 load! 4 shots under 2 inches with one flyer, (self induced no doubt). Group on target was a bit high but will work near perfect with a 6 o'clock hold. Still a bit left but that's the way it is with this ol revolver.

It's always good to hear about accurate 44-40 loads!!!!

On the Relative Burn Rate Chart, SR-7625 is next above (faster) than Unique.