44-40 Videos, Pressure Test Pressure Curves

[Outpost75]

Bravo Zulu, great work!

[Savvy Jack]

I took the best shot, from each recent thirteen 10 shot groups, that best represents the average pressure of that group and made a gif. The only "pressure spikes" observed with any of the 96 total tests over-all were the high power loads of fast burning pistol powders. There were no "pressure spikes" for any normal loads regardless of using pistol powders or rifle powder. Early black powder loads had the same pressure curves as several of the pistol powder loads used.

There are slower burning loads which have a shallow initial burn which the pressures drop by 1 millisecond. The loads that dropped pressure faster were typically the fast burning pistol powders near the Bullseye/Titewad/Red Dot/Clays/700X/Titegroup/WST/Trail Boss powder burn rates that drop down faster, giving the "pressure spike" appearance. Even then, the peak pressures from those particular charges exceed or would exceed 13,000cup/11,000psi MAP set for Winchester 73' and revolver use, only to be used in the Model 92' or Marlin type actions

All 96 tests results can be seen here

Some Pressure Test Curve Charts can be seen here





Smokeless Powder Pressure Curves, click for animation


"Pressure Spikes", or the lack thereof
1. Fast Ignition, Fast pressure drop
2. Fast Ignition, Slow pressure drop
Of which both already exceed 11,000psi

[Savvy Jack]

Black Powder Pressure Curve



Black Powder Pressure Curve, click for animation
I do not know the gif wont work, here is a link to all of them
https://sites.google.com/view/44winc...essure-testing

[Savvy Jack]

Here are the absolute simplest results in a timeline format minus all the important details

[HWooldridge]

Here are the absolute simplest results in a timeline format minus all the important details

Great summaries in this thread - thanks for your hard work. Reloder 7 seems to be the perfect powder if the user is not focused on BP.

I don't have a chrono but have been using 20+ grs of IMR 4198 with good accuracy and no signs of excess pressure - BUT - 9.0 grs of WW231 is more accurate with JK's 43-215C projectile and a real tack driver in my old El Tigre. Regularly produces one ragged hole at 50 yds and only opens up a bit at 100 because of my poor eyesight.

I wish I could find Reloder 7 but it's scarce as hen's teeth around here - I've looked in the local LGS and box stores to no avail.

[Savvy Jack]

Where are the Pressure Spikes?

I guess if compared to modern BP loads, all other loads produce pressure spikes?

This WST load is the closest thing I have seen to a Pressure Spike for loads IF USED in the Winchester 73' and Revolvers.

https://sites.google.com/view/44winc..._gWA248koljW9k