doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com Shot Column Heighth And Crossing Shots

I know that Burrard, Francis Sell and others have gotten into this and that I have dutifully read their goings-on, but time blurs recall. The basic thesis I remember is that a comparatively long shot column in a loaded shell tends to elongate more quickly than a shorter one and that performance price is paid by the former on a longer crossing target. My question is how great is that price?

Let me give a simple scenario here and see what can be learned: Both guns average 70% patterns at 40 yards. The target is moving at 90-degrees to the shooter at 30 miles per hour. Gun #1 is a 20 gauge firing a 1 1/8 oz. magnum load of 6s at a muzzle velocity of 1200 fps. Gun #2 is a 12 gauge firing a similar weight shot charge at the same velocity with an identical number of #6s. Further assume target size is the equivalent of a 9" circle. Questions are:

-What are the comparable pellet hits on the target? ( assume uniform 30" patterns as to shot dispersal )

-Assume the target is a big fat duck - - does one lose sufficent killing power in the 20 gauge to make taking that shot less prudent, or is the difference ( and I am assuming there is one ) inconsequential? I recognize there are various pellet energy factors that are sometimes used to make a killing prediction here, but they are blurred to memory, as well.

Last, and by all means, change the value of factors given here if they make answering easier - - perhaps using #5s instead of #6s. - - Just keep them the same, other than gauge.

Who said posts have to pose easy problems? Actually, all input is appreciated - including opinions, too.

Given this premise...."with an identical number of #6s".....I'm of the opinion all other variables are pretty much neglible.

In other words, IMO, 300 pellets launched at the same speed through a comparable choke will have the same practical performance, regardless of gauge. That's the null hypothesis and the burden of proof rests with those who disagree.

This might help a bit:

TOTAL SPREAD (inches)
From Field and Stream Sept 1964

YARDS
CHOKE 10 15 20 25 30 35 40

Full 9 12 16 21 26 33 40 inches

Modified 12 16 20 26 32 38 46 inches

Improved Cyl 15 20 26 32 38 44 51 inches

Cylinder 19 26 32 38 44 51 57 inches

Now fill in that pattern with the # of pellets in the load irregardless of gauge then calculate the energy retained by the size shot (I already have a headache :rolleyes: )

Bob, by far the best work on this I'm aware of was done by another Bob, Brister. The book is "The Art and Science of Shotgun Shooting" or a close facsimile of that title.

He had his (trusting) wife tow a trailer-mounted, elongated pattern paper at various speeds, ranges, etc., and tested the effects of stringing. Strongly recommend that info, and the whole book.

Ah, Fred, that's too easy. I do remember, though, that Burrard had some type of high-sided truck on which was mounted a huge steel plate - -driven around by some very trusting estate-hand.
Trouble is I loaned out that Burrard volume three years ago.

Do you recall Brister's conclusions? Shucks, I wonder if I've got that book somewhere . . . .

You seem to be equating longer shot column in the shell to a longer shot string. Even if that is so there's nothing you can do about it. The shot string, however long it is, is moving much faster than the target. If you miss in front with the first pellets in the string, it's not likely the target will run into the last. If you miss behind you'll miss with the entire string.
If you're using the same shot load with 12 and/or 20 gauge, I'm with Mike on thinking the difference will be negligible. The only significant difference will be the recoil, assuming the 20 ga. gun is considerably lighter in weight. JL

There is a guy in Okla. that does or did a lot of pattern testing on a revolving drum. I don't recall the name off hand exactly but want to say Larry Feland [sp?]. He was primarily interested in trap loads, but published some of his findings in a booklet. Perhaps someone here can post the name & addy for you.

To answer your question, 'how great is that price?' JL hit it, except he didn't put it in terms of milliseconds and that's all you have in front, a few milliseconds. Behind its moot, except when the third bird back from the one you were shooting at falls out of the flight, stone dead.

I don't think the length of the shot string is going to provide a significant difference in practical terms. However, I do believe in most instances the heavy load from a 20ga will not throw equal patterns to a 12ga with the same 1 1/8oz loads. There you may get a performance difference that does matter.

The vast majority of Burrard's testing was done with the standard British game load of 1 1/16oz #6 (british) size shot & was primarily for driven game shooting. He did do a limited amount with a 2 3/4" chambered gun firing 1¼oz of shot. He was "Surprised" to find there appeared to be no increase in shot string length. Due to high recommendations I purchased a copy of Brister's book. The only conclusions I could determine he arrived at was that Burrard was wrong in all he said, & if you wanted to reduce shot string you had to invest in WW SuperX/DoubleX (Winchester's highest priced shell). I then noted the book was published by Winchester Press. It now resides under about 6" of dust, but I use Burrard on a regular basis, as far as I'm concerned the best book on shotguns ever written. I realize that's contrary to many opinions here, but that's my opinion.

TW, you're surely not suggesting the third bird falls because of the shotstring remaining after a properly led first bird, are you? The third bird falls because of insufficient lead on the first bird, nothing to do with shotstring.