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Patterning 101....

Discussion in 'Shotguns' started by Dave McCracken, Mar 3, 2003.

  1. Dave McCracken

    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.
    Last edited: Apr 15, 2003
  2. jonesjj

    jonesjj Member

    This is Great information, Thanks for taking the time to write it out on how to go about doing it.

  3. sm

    sm member

    Well Done Sir!!

    Big advocate of PB's myself. So much info to be learned from them.
    Gun Fit, load, and components (wads, hard/soft shot,pwder meas...).

    Needs to be added to the top with other "Shotgunning 101" info.
  4. Andrew Wyatt

    Andrew Wyatt Well-Known Member

    Is this the same technique you use with buckshot?

    Would an 18 inch circle be more appropriate to judge buckshot loads with?
  5. Dave McCracken

    Dave McCracken Moderator In Memoriam

    Andrew, IMO, buck should pattern into 15" at the max distance it's employed for max effect and minimum endangerment of others. Measure your torso from side to side just below the armpits as to why 15".

    For HD inside, no problem. The worst ammo at max distance here at Casa McC would pattern into maybe 4", and my buck of choice half that or less.

    Outside, it's different. Here's where patterning is essential. My BOC goes into 16-20" at 25 yards, so max employment range would be around 20 yards under this rule.

    Some Southron deer hunters use handloads in overbored, long coned and tightly choked barrels to get much superior results. Naturally, they pattern religiously, oft as obsessed as benchresters.

    And while you're patterning your "Serious" ammo, see where your slug of choice hits in relation to the buck pattern.
  6. dongun

    dongun Well-Known Member

    Good stuff, Maynard.
  7. mcshot

    mcshot Active Member

    I found patterning particularly helpful during my trap shooting days.
    Those straight-aways I was missing on station 3 were mostly the result of a donut pattern.
    I changed wads and powder (red to green dot) and the pattern tightened right up. Lost an alibi but improved my scores.;)
    Good information!
  8. Guntalk

    Guntalk Well-Known Member

    Get Brister's Book

    Every shotgunner should have a copy of Bob Brister's book, "Shotgunning: The Art and the Science."

    Bob did a lot of experimenting, and though the book is probably 20 years old now, it still contains a wealth of information.

    Lots of interesting stuff on patterning shotguns.

    Remember -- There's shooting to see where the gun shoots, nd then there is patterning to see how the load and choke shoot.

    The two are quite different.
  9. ahadams

    ahadams Well-Known Member

    I just ordered Brister's book from Amazon.com where it was 5 bucks off, by the way...
  10. Still Learning

    Still Learning Well-Known Member

    Great suggestion about the grids!

    I'll get my 11 year old to make Daddy some patterning papers in the next week or so. She likes doing things like that. My 870 is supposed to be out of the shop in about 2 weeks. Its pattern was really poor with all ammo. When it comes home it will have a lengthened forcing cone, screw in chokes (Remington), and Scattergun ghost ring sights.

    This post also reminded me of my college days managing a city owned trap range. I built a patterning frame and kept cardboard and butcher paper on hand for anyone who wanted to pattern their handloads. That little gesture really won the hearts of our shooters and I can't tell you how much free beer and ammo I was given for doing that:D .

    Had I known about the grids and the highlighter someone might have paid my tuition for a semester!

    Thanks for the tip!
  11. Cooter Brown

    Cooter Brown Well-Known Member

    Wadwizard Choke Tube

    Have you tried one of these with Buckshot? They really extend the effective range.
  12. Still Learning

    Still Learning Well-Known Member

    Paper For Patterning

    Taping the shorter sized butcher paper is a hassle and I'm lazy. Newsprint will work but the type can make counting the pellet holes a drag...especially for 45 year old eyes.

    Today I hit on something that most married guys can count on for patterning paper. The old Christmas wrap that your wife bought right after Christmas works perfectly. The back is WHITE! The sheets are plenty big.

    This November you've got some excuses to make or you can just go to the store and buy her some new wrapping paper. Or you can just say, "I don't know where it is. Where did you put it?"

    Drawback to this: You can't bring your patterns to the house or she will find it. Evaluate in the field and then burn the evidence.
  13. kudu

    kudu Well-Known Member

    New member here, thought I would share a way we pattern shot at our club.
    We have a large piece of 12 gauge thickness sheet metal hung up on posts at the end of our fields that we use for paterning light shot.
    Take a partial gallon of oil base paint, say a quart, preferably white or light colored, and add a quart or two of motor oil or vegetable oil, whatever is available, mix well and take a large paint brush and paint on the sheet metal. This coating does not dry but stays tacky, put an aiming point on the metal and blast away. The pattern shows up perfectly on the metal and then all you have to do is wipe it again with the brush and you have a new surface to shoot again and again. Rain doesn't even wash it off.

    Just thought it might be a neat thing for every body if you can come up with the metal.:)
  14. tech

    tech Well-Known Member

    Guys, I went by Sears and got a bunch of thier old boxes. I do spray on silhouette's and such, but I find a piece of cardboard handy to pattern on.

  15. Bob F.

    Bob F. Well-Known Member

    Your local newspaper probably has roll ends of news print lying around for free. Not sure about the newer presses but a few years back they changed the roll before it ran out, had a roll for every 4 pages, ie- a 12-page section ran on 3 rolls simultaneously, everything sinchronized. If a roll ran out it was kinda' like WD-40ing your primers! Kindergarten teachers and Artsy-crafters got a few of ours.

    I usually just buy brown wrapping paper for targets/shooting groups.

    Mr. McC, I gotta meet ya' one of these days! Maybe @ the Redneck Cup!
  16. P95Carry

    P95Carry Moderator Emeritus

    Holy Moley ..... how in Hades did I not see this was here . I mean .... only near a year ... sheesh!

    Oh well .. better late than never ... belated thx Dave for another most educational offering ... now wonder I'm a slow learner!:p

    CAPTAIN MIKE Well-Known Member


    ...THANKS for sharing your perspective. We all need to "get back to basics" in order to keep our skills growing in the right direction.

    Very Respectfully,
  18. dance varmint

    dance varmint Well-Known Member

    Good source for patterning paper: Cabela's. They used about 20 big sheets of paper as packing material in my last order. Unscrunch them, roll them up, and then all you need is your staplegun and cardboard backing.
  19. Drundel

    Drundel Active Member

  20. Nathaniel Firethorn

    Nathaniel Firethorn Well-Known Member

    Quadrille flip chart paper (available at Staples, Office Foo, etc.) has the one-inch grid lines already drawn.

    However, I tried Dave's method and found it very tedious to fill in the one-inch squares - on a standard 25 x 30 inch sheet, there are 750 of 'em, and that's just one gun/load/choke combination! :what: 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.)

    Can anyone here suggest some clever Photoshopping that can accomplish the same thing? :D (I.e., show where the pattern will, and won't, break a clay.)

    - pdmoderator

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