doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com Pattern theory

I was just thinking last night of such an experiment altho I wasn't aware it had been done. Didn't realize water wouldn't deform the shot. It would be interesting to take high speed, high resolution color pictures of such a load when fired thru various chokes.

It doesn't take a lot of deformation, as I understand it, to create more drag and cause the pellet to move to the rear and/or the fringe of the shot string. I have looked at high speed photography "stills" of the shot string and it is impossible to see deformation due to the poor resolution of such photographs. Tom has very strong evidence that the roundest pellets are the ones in the front and the core of the shot string. The more deformed the pellets, the more to the rear and the fringe of the pattern are their positions.

If you disagree with his findings, and can show cause where his experiments were faulty or faked, I suggest you call him yourself. He has plenty credibility, after decades in the shotshell ballistics field, to not need my defense.

SRH

Stan;
Thank so much for this report. I had really forgotten all about this test but since you brought it up I do recall seeing it & about the different colored shot layers. Just another of the bits & pieces I have stored to memory but can't always bring to mid just here I picked up different bits of info. This certainly goes right along with several of us have been saying all along with some actual testing to verify.
As you say of course there are those who still won't buy it, but a lot will.

Relax. I said nothing about disagreeing with his findings nor anything about his experiments being faulty or faked.

Thanks much also Stan. I doubt all would accept it as fact, but still you've shown us one place to look. Did he mention what caused that lower third of the shot column to show more distortion? I suppose if we assume they're all distorted the same, and crack open the ole text book, then some equal but opposite force acted on the top third. But, except for the blowup pictures, there doesn't seem to be much holding the shot in barrel when a shell is lit off.

I did not intend that last statement about disagreeing with his findings to be toward you, cpa. But, reading back over it I see that it certainly looks like that. It was originally directed at those who doubt any findings, by researchers, that don't agree with their own. I did not do a very good job of expressing myself. My bad.

SRH

Thank you Stan for your research with Tom Roster.

No problem, there was really a lot of luck involved. I thought I remembered someone doing that test many years ago, but didn't remember enough to post about it. I figured if anybody would know if some kind of test like that had been done it would be Tom. It was just kinda like a burr under my saddle, if you know what I mean, until I found out.

I am thankful to Tom for decades of no-nonsense shotshell ballistics research and study, and to Dave for providing us with this forum to discuss it.

All my best, SRH

Stan, that's a test I hadn't heard of before. Certainly looks to be pretty solid evidence that the rear pellets deform more. Thanks for doing some digging.

There would seem to me to be NO mystery as to why the deformation occurs more in the rer pellets than the front ones.
When he shell is fired the pressure "HITS" the shot in the rear. The rear shot have the weight of all those in front of them to move while the front ones are only pushing air.
Take a lead bar & lay it down on its side. Smack one end gud'n hard with a hammer. see which end is swelled, the end where you hit it or the other.
Forget all the scientific theory that has been spouted & use your brain a bit. Tom's experiment that Stan has quoted has verified this but this is what would have been expected all along.
That 1400 something psi per Brinell hardness number I quoted earlier for the deformation of lead is actually 1422 psi. I first encountered this in reading about cast bullets in revolvers where it was stated the bullet should not be so hard as to resist bumping up to seal the chamber throat. Not sure about the spelling but the 1422 psi was cited from Veral/Vernal Smith. A bit of research shows this is actually the figure in determining Brinell Hardness which is based on Kilograms per Sq MM. 1 Kilo per 1mm converts to 1422 lbs per Sq In. thus if you smack the shot with a 10K psi load the shot will have to have a Brinell Hardness of 7 to resist deformation.