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doesnt constriction determine the choke

Discussion in 'Uncategorized Threads' started by ColBuckShot, Feb 15, 2008.

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  1. ColBuckShot

    ColBuckShot TS Member

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    Im confuesd again, doesnt the amount of the constriction determine the choke.
    Regardless of overboring, backboring, barrel size etc. another words .025 is improved mod for all guns with that amount of constriction.
    Shell shocked in sunny Florida
     
  2. halfmile

    halfmile Well-Known Member

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    No, it's the percentage of bore reduction.

    25 thousandths in a .410 is a lot tighter than the same amount in a 10 guage.

    Draw a couple circles on paper and figure it out. Other factors come into play also, such as leade angle and parallel section.

    HM
     
  3. ColBuckShot

    ColBuckShot TS Member

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    Halfmile thank you for your responce, but of course im only comparing 12 gauges here.
    You answer of percentage is the first i ever heard of this and totally confuses me. Please come back with a sanity check for me.
     
  4. ColBuckShot

    ColBuckShot TS Member

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    Mia you missed the whole point of my question.
    Is the amount of constriction used to determine the choke identification for all 12 gauges. In other words are all .035 restrictions indicating a Full choke
    regardless of bore dia.
     
  5. mixer

    mixer Well-Known Member

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    In a 12 guage barrel where bore diameter can be anywhere from .729 to .740+, a .35 constriction would be considered a full choke. The only true way to know exactly would be to pattern the gun.


    Eric
     
  6. Jim101

    Jim101 Active Member

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    ColBuckshot, Generally speaking the amount of constriction is used to determine choke. There will be some variances but they will be small. The true measure of the choke is how it patterns.

    I'm sure there will be numerous experts, Pontificators, Soothsayers, And DRs of prevarication add a multitude of ifs ands and therefores to this thread.






    Jim
     
  7. Neil Winston

    Neil Winston Well-Known Member

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    CBs, there are two ways to define choke.

    1. By dimension, and here your 0.025 is about IM

    2. By performance. Here the IM is a pattern percentage of between about sixty and seventy percent at forty yards.

    The two ways are independent. Though a measured IM choke may pattern within the required range, it may not. Similarly, a gun shooting that sort of pattern may have a constriction of about 0.025 inches, or it may not.

    Often a gun will fall under both definitions. In fact, if you know one of the numbers, if you bet on the other to about match you will probably usually win and if you are wrong, it will be because you underestimated the tightening effect of measured choke. For example, the lower barrel of an MX-2000 I have measures but 0.023 in choke but shoots above 70% with good shells at 40 yards.

    Halfmile, it's "lede" not "leade" (or lead).

    Neil
     
  8. JJJ

    JJJ TS Member

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    I read this somewhere, I can't remember in what publication.
    However,here is what I wrote down:
    LM=.015 constriction,M=.020 C,LIM=.025C,IM=.030 C,F=0.35C, & last but not least
    super full=..040 constriction. Does this answer your question?
    JJJ
     
  9. tcr1146

    tcr1146 Well-Known Member

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    I think he wanted a simple answer to: Is a .750 bore with constriction to .715 a full choke just like a .740 bore to .705 constriction the same full choke! Simple answer is yes regardless of the club experts bull! Tom Rhoads
     
  10. hmb

    hmb Well-Known Member

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    Never heard of the percentage of constriction method. To my knowlege smaller guages reguire more constriction. to get the same results as larger guages. HM is there any documentation available on this topic. HMB
     
  11. ivanhoe

    ivanhoe Well-Known Member

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    I don't know what all the debate is about. I you put any store by what Briley has to say try the Website URL above. They say that it depends on bore Dia. and they have constrictions accordingly. The one above is a standard bore Dia.

    hmb Briley says that full in 12ga. 0.035 and in 20/28 full 0.027 but of course we all know you know more about it than they do.

    Bob Lawless
     
  12. MTA Tom

    MTA Tom Active Member

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    Isn't the choke a function of the difference in the area measurement? The diameter is just a convenient shorthand.
     
  13. ColBuckShot

    ColBuckShot TS Member

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    I would not have thought the question I asked would have returned such conflicting responces. I think tcr1146 understood my question and hopefully he is corrct.
     
  14. Mike Battista

    Mike Battista Well-Known Member Supporting Vendor

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    Col Buckshot,
    If you are near the Silver Dollar Club, drop in. I'll measure your guns bore and choke and take you to the patterning board.
    Mike Battista
     
  15. Neil Winston

    Neil Winston Well-Known Member

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    Both Dr. AC Jones and I have gotten our tightest patterns from chokes about 0.040 inches in restriction no matter what the barrel diameter. I've never seen any evidence that a barrel of 0.740 or therebouts and a choke of about 0.033 is, in general, tighter than - or usually even as tight as - one starting at 0.729 and closing forty thousandths. Or starting at 0.740 and doing the same.

    They are all full-choke in performance, however; just some are more full than others.

    Neil
     
  16. ColBuckShot

    ColBuckShot TS Member

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    Im wishing this didnt turn in to a can of worms for me, I get confused easy enough as is.
    My gun is a Kolar @ .750 bore, SOOOOO does this mean that .035 is full as in all other guns with a bore of .729 and up.
    ORRRRRR does this mean Id use a little less constriction to get a full choke.
    Ive patterned my gun at 35yds with .025 and it seemed to fill up the 30 inch circle, but now after reading these responces Im not sure if I need a brain surgeon.
     
  17. ColBuckShot

    ColBuckShot TS Member

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    So pick a Door please.
    Door #1: As the bore increases, the constriction can Decrease in order to produce a full choke ex. .750 minus .030 would equal full choke.
    Door #2: Simple math is correct
    ex. .750 bore minus .035 is same as .735 bore minus .035 both equal full choke.
    Door #3: nut house
     
  18. Smiley

    Smiley Member

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    I'm interested to see that a lot of you dont seem to know what the measurement for 12 gauge is.It is the diameter of a ball of pure lead,this comes from a standard from english gunmakers that 12 of these balls are 1 pound(eng) per se 20 gauge 20 balls .The exception being 410 which is a linear measurement(0.410 inch).therefore 12 gauge is a defined measurement of .730 inches and this is what your chamber will be as to the barrel diameters these will vary considerably according to maufacturers.The constrictions are measured according to the barrel diameters.The regulation of choke (ie full,mod etc)should be carried out using the shotshell that you prefer so that the best pattern is achieved.
    Paul
     
  19. ColBuckShot

    ColBuckShot TS Member

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    Please see my options above, vote early vote often.
     
  20. waverider

    waverider Well-Known Member

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    Colbuckshot,

    History of chokes constriction as I see it.

    Switchblade has the historical definition, this was developed when almost all shot shells were basicly made the same. Brass base, paper hull, most likely black powder, over powder card, felt wads, and over shot card. The corresponding constrictions were: Cyl no constriction, Skeet .005, IC .010, Mod .020, Improved Mod .030 and Full .040, gave the percentages at 40 yards.

    Then Sk##t shooters felt that they needed a choke in-between IC and Mod for shoot off doubles, so .015 constriction choke was made and called Skeet 2.

    The birth of sporting clays and shooters wanted chokes at .005 increments. So most after market companies and even some of the big boys follow the Briley chart.

    Now with the numerous different wads and powders, I feel that the pattern percentage chart is now obsolete like the "dram equivalent". I hope the industry now just follows the Briley chart. FYI the older Browning Invector Plus flush mount chokes were develped to shoot the percentages at 40 yards so they will have less constriction than the Briley chart. You need to pattern your choke with what ever ammo you are using and find the constriction that does you want. The real test how ever is how target breaks when pointed at perfectly.

    Another FYI, Perazzi uses a metric system of constriction. 1=.004, 2=.008, 3=.012, 4=.016, 5=.050, etc.

    Jason
     
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