Dave McCracken
Moderator In Memoriam
Patterning is generally considered a bit of a pain. It's also as essential as breathing to a shotgunner.
NOTHING good can come of a shotgun/load/gunner combination until you establish a link between Point Of Aim and Point Of Impact, AND find out what a given load will do at a given range from THAT shotgun and choke.
Patterning will do both. It take some time and a bit of effort,but yields dividends in short order.
Technically, finding POA/POI isn't patterning per se. But, we can do both here and save time.
Here's what you need....
Some kind of target holder that will support a 4' by 4' sheet of paper. A large cardboard box wil do. Butcher's paper, blank newsprint, or art paper will work as targets.So will the commercial targets some ranges and gunshops sell.You want at least 5 sheets,ten is better.
Blank is best, though a reference point at the center is good. I like a simple dot.
Even better, though hard to find, is paper with a one inch grid laid out on one side faintly enough that it cannot be seen from the firing point. More on this later.
Establish what distance you want to pattern at. For HD use, measure the longest shot opportunity possible and add a yard for GPs.For quail hunting, etc, 25 yards makes sense, 35 for trap, and so on.
Attach the paper to the backer and get ready.
Folks differ on the next part. Some want to benchrest the shotgun and aim from a solid position. I'd do this for a turkey load, since most turkey hunting involves shooting from a rest.
But most shotgunning is dynamic, shooting at something moving fast. These are not aimed shots, but pointed. So, using a good stance and mount, shoot as if that aiming point was a bird going straight away.
Next, make your shotgun safe and mark the target with pertinent info like load, choke and distance.
Remove the target for later evaluation, stick another up, and repeat until you've 5 targets.
Repeat with any other chokes,loads or distances you want to know about.
Now you've got raw data. Here's what to do with it.
The classic approach is to draw a 30" circle around the apparent center of the pattern, NOT the reference mark, and count all those tiny holes. Not mandatory, so relax.
First, though let's find out where the Center Of Pattern falls in relation to where we were looking. Eyeball this and then measure between COP and reference point. If it's centered left/right and either right on or a bit high, Huzzah! it's shooting where you're looking.
NOTE: British folklore attributed to Robert Churchill says that if patterning at 16 yards, a 1/16" change in the stock moves the pattern 1". I doubt it's that simple, but it could give you a starting point if POA and POI don't coincide.
Now let's look at all those little holes. What we're looking for is where the holes aren't, inside the pattern. Places where there's less than one hole for every 2 square inches. Or, any place where a standard clay pigeon could fit without covering at least 3 holes.
Here's where that one inch grid graph paper is handy.Startingf from the center of the pattern, use a bright hilighter to color in all the places where two adjacent squares are unmarked.When done, you've a pretty good idea of where your pattern is strong and where not. I'd regard a pattern with more than two unmarked areas of 2 sq.in. as patchy(Re Oberfell at al) and not for use at that distance.
A pattern, remember, is a two dimensional record of a three dimensional event. The shot cloud elongates as it hits the air, and may be over 12 feet long at 40 yards. So, just because there's no patches in the pattern doesn't mean all those pellets will arrive simultaneously.But a patterning session like this will help immensely in your progress as a shotgunner.
NOTHING good can come of a shotgun/load/gunner combination until you establish a link between Point Of Aim and Point Of Impact, AND find out what a given load will do at a given range from THAT shotgun and choke.
Patterning will do both. It take some time and a bit of effort,but yields dividends in short order.
Technically, finding POA/POI isn't patterning per se. But, we can do both here and save time.
Here's what you need....
Some kind of target holder that will support a 4' by 4' sheet of paper. A large cardboard box wil do. Butcher's paper, blank newsprint, or art paper will work as targets.So will the commercial targets some ranges and gunshops sell.You want at least 5 sheets,ten is better.
Blank is best, though a reference point at the center is good. I like a simple dot.
Even better, though hard to find, is paper with a one inch grid laid out on one side faintly enough that it cannot be seen from the firing point. More on this later.
Establish what distance you want to pattern at. For HD use, measure the longest shot opportunity possible and add a yard for GPs.For quail hunting, etc, 25 yards makes sense, 35 for trap, and so on.
Attach the paper to the backer and get ready.
Folks differ on the next part. Some want to benchrest the shotgun and aim from a solid position. I'd do this for a turkey load, since most turkey hunting involves shooting from a rest.
But most shotgunning is dynamic, shooting at something moving fast. These are not aimed shots, but pointed. So, using a good stance and mount, shoot as if that aiming point was a bird going straight away.
Next, make your shotgun safe and mark the target with pertinent info like load, choke and distance.
Remove the target for later evaluation, stick another up, and repeat until you've 5 targets.
Repeat with any other chokes,loads or distances you want to know about.
Now you've got raw data. Here's what to do with it.
The classic approach is to draw a 30" circle around the apparent center of the pattern, NOT the reference mark, and count all those tiny holes. Not mandatory, so relax.
First, though let's find out where the Center Of Pattern falls in relation to where we were looking. Eyeball this and then measure between COP and reference point. If it's centered left/right and either right on or a bit high, Huzzah! it's shooting where you're looking.
NOTE: British folklore attributed to Robert Churchill says that if patterning at 16 yards, a 1/16" change in the stock moves the pattern 1". I doubt it's that simple, but it could give you a starting point if POA and POI don't coincide.
Now let's look at all those little holes. What we're looking for is where the holes aren't, inside the pattern. Places where there's less than one hole for every 2 square inches. Or, any place where a standard clay pigeon could fit without covering at least 3 holes.
Here's where that one inch grid graph paper is handy.Startingf from the center of the pattern, use a bright hilighter to color in all the places where two adjacent squares are unmarked.When done, you've a pretty good idea of where your pattern is strong and where not. I'd regard a pattern with more than two unmarked areas of 2 sq.in. as patchy(Re Oberfell at al) and not for use at that distance.
A pattern, remember, is a two dimensional record of a three dimensional event. The shot cloud elongates as it hits the air, and may be over 12 feet long at 40 yards. So, just because there's no patches in the pattern doesn't mean all those pellets will arrive simultaneously.But a patterning session like this will help immensely in your progress as a shotgunner.
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It seems like the kind of thing that would be cake for a computer to do, though (take a digital picture of the pattern and apply some really trivial image processing.)
