Always check at the patterning board.....ALWAYS!

Discussion in 'Trapshooting Forum - Americantrapshooter.com' started by forrestmohrman, Sep 21, 2021.

  1. I just returned from the fall classic at the cardinal center. I shot wed. thurs. and fri. Singles and handicap all three days. I shot 95 all three days on singles but with the same gun shot 93, 87, 88 at 20 yards. One would assume I am just a horrible shot at the 20. Me too! Upon coming home a little man in the back of my head said that I missed 5 shots that were straight aways and I knew I should have hit them! Why?

    When I got home I "single shot" patterned the gun at the 35 yard line and the pattern looked OK....both up and down and left and right.....the pattern density was pretty dense. Dense enough to break birds at the 16. Then I patterned the the same gun at 40 yards. Simulating the 20 yard handicap. The change was incredible! Very few bb's existed on the board! There were several holes where the bird would not be struck by a single bb!

    So I started looking at the choke and all of the other chokes that came with the gun. A previously owned gun! As I started looking for obvious signs of trouble I just happened to put the calipers on the ID of all the chokes. I noticed that not all the chokes had the same Inside diameter on the breech side! This got me wondering and led to researching the problem. I found that ceaser guerini had made two different barrel diameters .......735" and .745". Some of the chokes were .735 and others were .745. I checked my barrel and it was marked 18.7MM = .736". The choke I was using was .745......the wrong size for the barrel of the gun producing a reallly screwed up pattern.

    I then put in a .735 choke and repatterned....... the pattern was very good. Just a .005" error could make that much of a difference was amazing to me. Live and learn!

    Whenever buying a used gun know what you are getting yourself into. As I am now starting to see, used guns are not on the used rack just for the grins......they generally have something going on that the previous owner did not understand or like.

    I now wonder what my scores could have been with the right choke in the gun day one?

    Thank god I spent 48 years as a design tool and die builder!

    I help teach trapshooting for the clay target league children. Always check the patterning board when in doubt!
     
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  2. In addition to the choke issues I decided to build myself a 4ft x 4ft paper pattern board and try out some different chokes. My endeavor lasted 5 days and I had tested every choke I owned plus a few new ones from EXTREME CHOKES and COMP-n-CHOKE. The results were shocking to say the least.

    My research to go this route started with a article about patterning density......in percentage comparing the number of bb's in a 30" ring Shot at a distance from 40 yards. I remember one of the staff guys from Dawson Enterprises mentioning this to me about Pat McCarthy. Pat would do this type of patterning from time to time. The article I read on pattern uniformity and pattern density just reinforced my desire to try it out.

    I spent 5 days patterning 20 different times with different chokes with the same loads every shot. So I ended up with my basement floor covered with test patterns. I marked every test and counted every bb hole in a 30" ring and compared it to the number of counted bb's in the load. Divided one into the other gives me the percentage of pattern density. As I went thru all of the test patterns I noticed some holes/hollows that seemed to occur from shot to shot inside the pattern with different chokes. That got me wondering about how to fix this. The end result was testing every different barrel from my combo gun with all of the different chokes. The results were astonishing! Not all chokes work like we were led to believe. Who would have ever guessed that a IM choke of .025" would generate a 78% pattern density at 40 yards with a 34" barrel? And who would have ever thought that same exact choke in a 30" barrel would produce a 67.7% pattern density. Same gun.....same choke...…same load....same distance....different length barrels?

    When the data was all collected I found that by using the same shell....each barrel had to be choked differently to produce a pattern density above 60% without holes in the pattern.

    Further testing I am sure would change all of this data collected If I were to change the shell, or the powder charge, and the load size.

    So at the end of the day I have stumbled onto something for me that will change my thinking about chokes, patterning boards, and paper patterning. Patterning boards / grease boards are useful to find out if your shots are in alignment with how you shoot the gun. Also the elevation can be found out as well in comparison to your point of aim to the point of impact at a given distance.

    But if you want to know and see pattern density and pattern uniformity one must use the paper pattern and find the percentage of density.

    Getting back to the previous thread from the cardinal shoot......that 34" barrel I was using produced a 54% density with a large hole in the lower left quadrant. By changing chokes I was able to obtain a 78% density. The choke is a ported style and I will leave it unnamed. BTW...I just shot a 23 the other day at the 27 yard line using a .025 choke! Who would have guessed? I was led to believe this was unobtainable! Must use a full choke at 27 yards!!!

    My point is.....do your homework and find a choke that will work for your gun, shell, and load. Paper is the way to go!

    For you shooters that score above 90% and want to do better!.....you need to know what your pattern density and pattern uniformity is, or you are just guessing what is wrong.
     
  3. Unit88

    Unit88 Member

    I enjoyed reading your two posts.....I remember in the early 90's my son was a freshman and on the A team of our local high school trap team. One of the old timers at the CF gun club told me how to pattern his shotgun. We made a frame and bought a roll of brown paper. We tried different loads and found a load that really patterned well. (no holes and great uniformity) That exercise was a confidence builder for him. He shot that load all 4yrs. I agree it is the only way to "know" what your load is doing, but I still hate to count pellet holes.
     
  4. puablo

    puablo Moderator Founding Member Forum Leader Member State Hall of Fame

    JMO---
    I have been shooting ATA since '63 and never have and never would put the gun to the pattern board (especially a brand new gun that I had purchased and cannot return or trade back from the dealer)...my feeling was that if you found out the gun 10 " to the right and no way to correct it, you are screwed ...Again like I said just my own 2 cents
     
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  5. michigan_berry

    michigan_berry Active Member

    “I bought a car that pulls to the right. Instead of putting it on an alignment rack and fixing it, I’m going to learn to drive it that way or just not drive it anymore.”

    If there’s a clear or even suspected issue, why not try to figure out what’s wrong?
     
  6. rookieshooter

    rookieshooter Mega Poster Forum Leader

    Maybe some of those 3rd place Lewis wins might had been 1st place wins had you only put it on paper? How do you properly adjust an adjustable comb without putting it on paper? By target breaks?
     
  7. puablo

    puablo Moderator Founding Member Forum Leader Member State Hall of Fame

    Maybe, maybe not---like I said, just my opinion---
    Check the record book of some of the greats (Arnold Rieger)---shot a Winchester model 37--- no rib, no nothing,and won everything imaginable---record long runs. etc..just sayin. Every person has their own way of achieving success... and if it works, God bless them

    Have a great day buddy
     
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  8. Justin L.

    Justin L. Active Member

    I haven’t ever patterned a target shotgun and have been shooting for about…27 years? I adjusted the comb by the breaks I was getting and always just screwed a Full choke in- or IM for the first shot of doubles. I think it’s hasty to say you need to pattern every gun, but if it helps you- go for it. The used gun and getting the wrong choke deal would be a bad deal, but I’ve also bought and sold a lot of target guns and never had that issue (that I know of).
     
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  9. Kyle Kanuha

    Kyle Kanuha Member

    I agree with OP on patterning a gun for pattern performance. He didn't say POI but I like patterning for POI as well.

    I like patterning because of cost effectiveness. At most, it's a box of shells and larger peices of paper. So what's that, like $15 total ?

    Now go to a trapshoot. You pay for targets, shells, and options. You never patterned for POI or performance. You shoot HOA and wonder " hmmm that was weird. That should've been a hit" .

    Then the Shoot is over, a week later you decided for hell of it, I'll shoot it on paper. You shoot it in paper and it's WAYYYY different than you thought while just shooting clays. Make adjustments and got it dialed to what you think it is. Scores go up after patterning, even if it's 1 target per 100 singles.

    My point is, it's WAY cheaper do it on paper, than to drop $1000 at a shoot and learn the hard way.
     
    rookieshooter likes this.
  10. jamesbalog

    jamesbalog Mega Poster

    I refuse to pattern a trap gun unless there is something clearly wrong.

    If the gun breaks targets i dont want to put it on paper to find something "wrong" that will get stuck in my head
     
  11. Justin L.

    Justin L. Active Member

    Well- sure it would be foolish to go to a shoot and spend $1,000 and the gun doesn’t shoot where you want it or doesn’t pattern correctly. By shooting enough practice before that shoot, you would have everything ironed out, as well.
     
    Flyersarebest likes this.
  12. wpt

    wpt Forum Leader Founding Member Forum Leader

    I use the pattern board for Point of Impact ONLY, being as there are no two shells exactly alike it is impossible to duplicate a pattern anyway so it is a waste of ammo ... The pattern board gives you the pattern at that specific point (static pattern) so any distance closer or farther away the pattern will in all probability not be the same as it is at the spot where the impact is at the place (distance) where the pattern board is setting ... WPT ... (YAC) ...
     
    Last edited: Mar 28, 2022
  13. LCH

    LCH Mega Poster Forum Leader

    IMO POI is about the only meaningful thing you can take away from a patterning board. I've wasted countless hours, $$$ and old blueprints trying to cram 90% of my pattern in a 30" circle. What I realized is a payload on paper and a payload on a trap target are two very different things and one should not be used to interpret the other.
     
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  14. Flyersarebest

    Flyersarebest Moderator Founding Member Forum Leader

    Hey Bud, I saw your score on the board inside, nice shooting.

    Thanks, I picked that gun up a couple of weeks ago. Shot it a few rounds and it fit so I bought it.

    Yeah, when you run them I guess you could say it fit.


    I'll tell ya, I've had straights before with other guns but this one really smokes them. I mean some of them were just a solid Black ball. It was just smooth and seemed almost easy to break them. I mean I had to concentrate and all that but if I just focused on the target I crushed it.

    That's great, good for you, congrats. You gonna keep this one?

    Not sure yet, I have to go pattern it to see where it shoots.
     
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  15. LCH

    LCH Mega Poster Forum Leader

    On the flip side, a friend just bought a fixed rib Seitz. Shot an 8 with it from the 16. So to the pattern board he went. He shot the top of the board. Came to find out it shot a good 24" high......
     
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  16. rookieshooter

    rookieshooter Mega Poster Forum Leader

    I've had so many ribs made over the past few years I've lost count. Some made by Simmons, some by Eubanks, some by Keen and now me. In fact once I receive shipment of more steel rib material going to design a one of a kind break away rib due to it's extremely high height.
    What I'm getting to, is that each one I put on paper for POI ONLY. Then all there was to do was to adjust comb.
    Due to the 4.5'' high sighting plane the cast off was always my biggest concern. In fact I can narrow it down to one sentence ''They all shot to the left'' with the comb directly in line with barrel.
    No matter if it was green dot, red dot, PB, 9 shot or 6 shot, the all shot to the left.
     
  17. firewagon

    firewagon Active Member

    The guy is correct in stating that chokes play a huge role in pattern effectiveness. I have had the same issue with chokes. Same gun same two chokes I/M one shot spot on, the other was horrible. I went through all my chokes and discovered two more that were basically worthless. Opened my eyes....
     
  18. rrisum

    rrisum Mega Poster

    I agree 100% -- It is surprising the number of good shooters that can't tell where their gun shoots - I run a monthly raffle - selling posted notes with your name and a dot on it . the winner from the previous month shoots the 30 inch target at 30 yards-- closes BB to the dot wins half the pot , most BB's gets a bottle of my home made wine --In the last year we have had three shooters miss the hole target.
     
  19. CB630

    CB630 Well-Known Member

    I want the three shooters who missed to my right when shooting games
     
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  20. Edward M. Fish

    Edward M. Fish New Member

    I went a little overboard. I had three shotguns and multiple choke tubes for each. Purchased a 18" dial bore and 1) checked a actual bore size of each shotgun and 2) checked the actual of each choke tube.This way I knew exact amount of choke I had with each tube. Expensive but very interesting.
     
  21. rookieshooter

    rookieshooter Mega Poster Forum Leader

    Some people will do anything to get a yard off ;)
     
  22. Tsphens

    Tsphens Active Member

    Shooting enough practice before the shoot, would give you closure and time to figure out any lapses.
     
  23. amboy49

    amboy49 Well-Known Member

    First, I would think that someone who was a moderator would have a general working knowledge of gun dynamics and the importance of gun fit/pattern density/point of impact. To say there is no reason to know where a gun shoots is a hollow statement at best in my opinion.

    One of the best trap shooters I know who has won national events told me if you don’t at least shoot your gun to determine point of impact you’re an idiot.
     
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  24. Flyersarebest

    Flyersarebest Moderator Founding Member Forum Leader


    Since I'm the only "moderator" that posted on this thread I can only assume your not too thinly veiled swipe was at me. I had to double check your sign on name. For a second I thought winston actually did pull it off and came back on Easter Sunday.
     
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