44-40 Videos, Pressure Test Pressure Curves

[Bryan Austin]

Over the past few years I conducted 83 ten shot tests using the PressureTrace II system. Recently I decided to try and open up a comparison chart using overlays in the Gimp editing software and make some videos out of them..

It is not the best but I think it is certainly good enough for discussions.

It took me a while to satisfy myself as to the accuracy, but with the discovery of a few missing links, in general, everything is 100% consistent with reloading manuals and factory ammunition.

Rather than do one video at a time, once or so a week, I decided to dump a few all at one time. Check the website link below for updates.

For CAS, I made some Black Powder, Trail Boss and Unique tests that have been published.
https://sites.google.com/view/44winchester/chasing-the-44-40/handloading-introduction/pressure-testing/pressure-trace-videos

[Trailrider]

Fascinating! I do wish you would have shown one of the "standard" loads of 8.0 gr. Unique 200 gr hard cast bullet, as well as some of the loads using ReloadeR 7. The premature shotstart you mentioned could be the cause of destructive overloads if a bullet lodged in the forcing cone of a single-action revolver, where the powder isn't fully brought to stable burning pressures of 5,000- 7,000 psi.
Keep up the good work!

[Bryan Austin]

Fascinating! I do wish you would have shown one of the "standard" loads of 8.0 gr. Unique 200 gr hard cast bullet, as well as some of the loads using ReloadeR 7. The premature shotstart you mentioned could be the cause of destructive overloads if a bullet lodged in the forcing cone of a single-action revolver, where the powder isn't fully brought to stable burning pressures of 5,000- 7,000 psi.
Keep up the good work!

Excellent information, thanks for stepping in.

The 7.9gr Unique load with the 427098 should be close enough. An important note is to observe bullet diameter, bore size and seating depth. oddball design bullets can be problemsome.

[cpt dan blodgett]

Sadly do not have the Accurate mold specified for 215 Grain bullets.  I do have the better part of 1000 of desperado .428 205 grainers.  Would your Reloader 7 and IMR 4198 loads from the custom loads section work with those bullets?  I normally shoot Cowboy action with reasonably mild loads, but there could be some utility to having a 1300 FPS rifle load to shoot long range competition with targets at 80 and 100 yards routinely.  I do have the Accurate 43-215 C mould that should drop a 205 to 210 grain bullet depending on alloy.

[Professor Marvel]

thanks very much Bryan!
your work is greatly appreciated and I am grateful that you are sharing it!

Jack Christian would be proud!

yhs
prof marvel

[Professor Marvel]

Bryan -

I see your data corroborates cllaborates confirms the belief that Trail Boss is not only "faster burning" than Unique, but also
the pressure curve has a sharper initial slope ...

I am intrigued by these findings of yours:

"Replicated vintage black powder loads used pre-1884 unheadstamped cases that have the largest inside balloon pockets available. They created the highest pressures and fastest velocities, as advertised during that timeframe. I believe this to be due to the amount of powder that is down beside and "beneath" the initial ignition of the powder...possibly creating a "boost". The more shallow the pocket, the less "boost" created.

WRA era headstamped cases have a more shallow balloon pocket and produced medium pressures and medium velocities, consistent with advertised ballistics of that timeframe.

Modern cases, such as Starline, have no balloon pocket and created the least pressures and slowest velocities. "

This implies a far more complicated burn-and-pressure model than most of us thought, dependant upon container and charge shape.

There have been many studies by the military regarding artillary artilla different shaped "holes" extending through
the length of the powder charge in artillary artillacannon shells ..

thanks very much, I do hope soemone with more expertise in this will chime in.

yhs
prof marvel

[Trailrider]

I'd really like to see some pressure-time curves shooting .44-40, 215 gr. hard cast bullets, sized .430" going through .425" throats and into the .430" groove barrels of Old Model Vaqueros.  I've got an Oehler 43 PBL, but would prefer not to mess up the bluing gluing on the strain gage. Plus the range I used to test at no longer lets me set up with 110vAC to power, and my batteries don't last long enough for a good test series. 

[Virgil Lantey]

Wow! What a massive amount of work! I don't shoot 44 WCF but I really appreciate all that valuable data and the effort that went in to getting it. A big thank you for that!
When searching for a powder for 45 Colt I settled on CFE Pistol because (according to Hodgon) it got me higher velocities at below SAAMI pressure. It might be a powder to experiment with in 44-40. I plan to work up a 45 Colt rifle only load using IMR4227 for my Winchester 1892 rifle.
Again, thanks for taking the time to share all your data!

[Bryan Austin]

Sadly do not have the Accurate mold specified for 215 Grain bullets.  I do have the better part of 1000 of desperado .428 205 grainers.  Would your Reloader 7 and IMR 4198 loads from the custom loads section work with those bullets?  I normally shoot Cowboy action with reasonably mild loads, but there could be some utility to having a 1300 FPS rifle load to shoot long range competition with targets at 80 and 100 yards routinely.  I do have the Accurate 43-215 C mould that should drop a 205 to 210 grain bullet depending on alloy.

They should work fine but unsure as to your accuracy results. You can always try a few and work up or down.

thanks very much Bryan!
your work is greatly appreciated and I am grateful that you are sharing it!

Jack Christian would be proud!

yhs
prof marvel

Thanks Professor, I hope he would if he were still here.

[Bryan Austin]

Bryan -

I see your data corroborates cllaborates confirms the belief that Trail Boss is not only "faster burning" than Unique, but also
the pressure curve has a sharper initial slope ...

I am intrigued by these findings of yours:

"Replicated vintage black powder loads used pre-1884 unheadstamped cases that have the largest inside balloon pockets available. They created the highest pressures and fastest velocities, as advertised during that timeframe. I believe this to be due to the amount of powder that is down beside and "beneath" the initial ignition of the powder...possibly creating a "boost". The more shallow the pocket, the less "boost" created.

WRA era headstamped cases have a more shallow balloon pocket and produced medium pressures and medium velocities, consistent with advertised ballistics of that timeframe.

Modern cases, such as Starline, have no balloon pocket and created the least pressures and slowest velocities. "

This implies a far more complicated burn-and-pressure model than most of us thought, dependant upon container and charge shape.

There have been many studies by the military regarding artillary artilla different shaped "holes" extending through
the length of the powder charge in artillary artillacannon shells ..

thanks very much, I do hope soemone with more expertise in this will chime in.

yhs
prof marvel

Those were my thoughts as well, the powder burns not only up and out, but down as well.