doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com Chamber/Forcing Cone question

Actually Ted, I think we hit the "ad nauseam" part awhile back. My comment was directed at the barrel pressure data for long obsolete powders from Burrard that the Preacher posted. I couldn't help noticing that of the two equal charges of Smokeless Diamond, the load with the heavier shot charge exhibited a greater pressure drop at 6" than the same powder and same charge with a lighter shot charge.

That flies in the face of everything I've seen when it comes to virtually any powder... rifle, pistol, or shotgun... pushing a heavier bullet or shot charge, versus the same load pushing a lighter mass. When I see something that defies the Laws of Physics, it tends to get my attention. The Preacher's reply, which included another old pressure curve, didn't answer my question. If anything, it confirmed that the data for Smokeless Diamond in his earlier post was suspect, and not just a fluke, because the pressure testing was apparently for an average of ten shots for each load.

greener4me suggested there might be helpful information published by Burrard
I don't have Vol. 2 of the 1931 edition, but found data in the 1955 edition, converted to psi, and posted because, unlike Ted, I find it interesting.
There are lots of vintage pressure - distance numbers here, which took some effort to find, and some turn-of-the-century experiments regarding chamber length and "turn over"
https://docs.google.com/document/d/1F2sQuPm05IE4VWYYnCkvuXmYEzQoWd_SQgaAfUOZEFU/edit?tab=t.0

The answer to your question keith is that the numbers are the numbers. If you believe Burrard did sloppy work, please find better numbers and post them.

Tried to find a digitized 1931 edition of Burrard and could not.
Possibly greener4me could post an image of the relevant study he mentioned.

IMHO the point of knowing vintage shotshell pressures is that 1) there has been a great deal of misinformation and 2) we can know, not guess, the ballistics of the shells for which our vintage doubles were designed. OTOH it's perfectly fine to just shoot and be happy

Preacher, I believe you unwittingly posted an error, and even after it was pointed out, you had no logical explanation.

I believe a commercially available gun powder that actually produced lower pressure at 6" with a heavier shot charge (all else being equal) would indeed be a miraculous thing.

I also believe that the "numbers are the numbers" Preacher. And numbers are nothing more and nothing less without meaning and understanding. For those who have some level of understanding, there is a time to trust the science, and there is also a time to question the science. We are permitted to question science (and internet experts) because sometimes, the numbers are just wrong, intentionally or accidentally. It's kinda like when your pal the Nutty Professor couldn't explain a wide disparity in published numbers for what supposedly constituted a lethal level of lead in the blood of eagles... Or how an eagle that was reported to have a blood lead level so high it was not only lethal, it was "off the charts". Yet that bird was found perched on a tree limb... somehow able to fly to get there. It's times like that when we see the difference between analytical thought and mere regurgitation.

I believe that there is a vast difference between posting data (ad nauseam---thanks Ted!) that you have accumulated in your scrapbooks, and actually understanding what you post. I think it was W.C Fields who said, “If you can't dazzle them with brilliance, baffle them with bullshit.”

Enjoy your shooting. Try not to flinch!