doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com Shot Distribution in Pattern

No, I'm not joking. Seriously not joking. Would you be so kind as to enumerate the forces and moments at work within the shot column during choke passage. What instantaneous forces and moments are present at the muzzle?

I can easily visualize these little spheres with all sorts of force and moment vectors acting on them. Unfortunately I don't know any way to know the value or direction of said forces and moments. It does me no good to know there forces and moments unless I can know direction and value. Do you know any way to use this information in a prediction formula?

DDA

Brent, I think I have figured out what you want. You want an equation that will spit out pattern diameter or maybe one sigma (normally distributed) with an input of gauge, % bore reduction of the choke, pattern distance, and maybe muzzle velocity and chamber pressure or bore pressure at the choke. How close am I?

DDA

Not very. But I'd be interested to see such an equation. That's always a good place to start and then work backwards from.

Sorry, I thought I was zeroing in on you wish. Would you restate it for me, please?

There is no such equation, to my knowledge. However, Dr. Jones's analysis program seems able to calculate a pattern's lethal/effective diameter based on one known pattern (10 samples) at a particular distance (yardage). The program also requires target susceptible area and number of hits for a lethal dose. And, you need to pick a required probability of a target break. Once you understand the shape and size of the effective diameter volume, you arrive at aiming error of the shooter as an input.

Lot of information in the above. It doesn't tell you how a pattern develops, but it does tell you how it performs.

Let me know if I am doing any good or if it is time for me sigh off.

DDA

I would be reduced to drawing pictures with little circles and arrows and I'm not gonna do that. The vector directions are easily perceived and the calculations/"equation" that you want are respectively not something possible except in an idealized (worthless) state and not I would even consider doing for free and the elements of variable stacking and individual choke configuration obviates the derivation of any equation in the real world as you well know.
I can however confidently predict that more choke constriction will generally produce smaller and denser patterns at any given distance. Usually.

P.S. BrentD is clearly pulling your chain. No one can be that obtuse and write mostly proper sentences. Wake up, Rocketman