44-40 Pressure Curve gif, black powder vs smokeless powder

For the smokeless powder gif, I took the best shot, the best that matched the average pressures from a ten shot group. The curves prove, for this cartridge, that there are no “pressure spikes” unless one uses fast burning pistol powders at higher than published loads, or for loads that require the use of stronger action rifles.

For the black powder gif, I combined what I could that gave a clear distinction between the years of manufactures…pre-1884, post 1884 and modern. These are years years of which the cases gradually lost the deep balloon pocket which appears to aid in higher pressures in black powder loads.

This screen shot shows the fast vs slower powders, the length of time it takes to complete the burn.

Give the gif time to load, it has been slowed down to 3 seconds per frame.
Smokeless Powder Curves1

This screen shot of the black powder gif shows just how much pressures original loads actually produced compared to todays loads. It also shows the length of time it takes to complete a burn. The hotter load retained higher pressures through the duration of the burn.

This black powder gif is extremally impressive
Black Powder gif

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:+1:

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Good you mentioned that, how did you collect this info?

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By conducting pressure testing shots and measuring the barrel expansion with a strain gage. Over the past couple years I made a minimum of 930 shots, 93 tests. I managed to attempt to learn how to take the information and work up gifs in GIMP and make some youtube videos and just make a mess, in general, of everything.

I tested,

  1. factory loads
  2. published handloads
  3. vintage loads (with great caution)

Details can be found here but I know most folks just don’t like to go read.

Also, folks can see my data on google docs here
44-40 Google Docs Data Cache

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That is awesome! I’m glad you envisioned the end results and had the patience to complete it. My :tophat: is off to you.

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When I was interested in 44.40 it was written that the unique case design shortens the life of the brass with anything but holy black.

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Wonder where that ‘bit o’ science’ came from…

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Myth
The older balloon pocket cases through the 1930’s were strong, but weaker than modern brass
This is the only failure I had during all of my 930+ shots tested. Of course I did not use these for all tests. However, this was done with black powder. I never tested smokeless powders in these type until recently which were not reloaded. I used old factory brass that was never fired.

In the beginning, Winchester did not want anyone reloading smokeless powder loads, but said if you did to use extreme caution.

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1907
1907a

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