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Discussion Starter #1
I think sometimes I am too data oriented. As a bit of a lead in, in 2007 I counted 89 patterns of different chokes and distances, and concluded you only have a reliable 20” inner circle to work with. Now that’s all I count when patterning. With respect to choke designations and related constrictions and pattern %, I have always referenced Shotgun Sports “Shotgun Barrels, Chokes ‘n Ballistics” page. I also know that current choke designation/constriction pairings are not the same as those published in Shotgun Sports. But does this mean anything, i.e. do all Full chokes regardless of manufacturer perform the same?. Recently I have been shooting a bit of bunker with a Wrights Full (0.032 constriction) and Light full (0.028) in my O/U using 7/8 oz. of 7 1/2s at 1345 fps. First shot breaks are at 35-40 yds. and I get some impressive hits. I patterned these chokes at 40 yds. along with my Beretta Full (0.038), one shot each, and counted the inner 20” circle. I fully understand the limitation of my sample size...but! If you take the Wrights Light Full (WLF) as 100% , the Wrights Full (WF) pattern is 14% more dense and the Beretta Full is 36 % more dense. If you consider the WLF constriction as 100 % the constrictions of the other chokes increases at the rate of WF by 17%, and the Beretta F by 45% ; reasonably similar to the patterning data. My conclusion is that pattern density and constriction are closely related...so? you will say. I then plotted constriction over pattern density and discovered the 3 points were in a straight line and that an increase of 0.002 in constriction resulted in an interpreted 6%-9% increase in pattern density in the inner 20” from the most open constriction to the tightest tested. Given my data is thin and the 6%-9% perhaps iffy, I believe the trend is certainly real and meaningful. If you managed to stay with me this far, thanks.

I then looked up the constrictions published for Wrights, Briley, Beretta, Browning, Kriegoff, and Kolar chokes, and also listed the insert in November 2013 Trap and Field (page 22) which are the same as the Kriegoff numbers. Looking at the choke constrictions of these 6 suppliers, none compare in total. The range of the variations in constrictions within a single choke designation , most tight minus the most open, are: XF-0.021, F-0.006, IM-0.006, M-0.006, LM-0.002, IC-0,005, SK-0.031 (no mistake, Beretta European SK choke is more open than the bore, I have one), Cy-0.012 (Browning Cy is more open than their SK which is 0.000). Given we are mostly a F, IM, M sort of crowd (ignoring the occasional XF user), given two shooters of equal skill, if one shooter uses a WF (0.032) and the other a Beretta F(0.038), a difference in constriction of 0.006, the shooter with the tightest choke could have a 20” pattern density 23% greater than the person using the most open. This certainly muddies comparison the water. Perhaps that's why there is so much debate about what choke works best for singles or from a certain yardage. Since there is no industry standard for constrictions, or none that anyone follows, you really don’t know what the true comparisons are between closely related chokes. Throw in softer shot (less expensive ammo?) vs. magnum shot and you may have another glitch. In spite of this, if our two shooters haven’t noticed any comparative difference in their chokes’ performance, perhaps they are throwing too much shot at the target.

I believe in his book, Dr. Jones mentioned that chokes should be sold by constriction, not designation. I hope this is evidence to support this. Now with respect to what constriction you should use, my pattern testing tells me that for our game, the more pellets you can keep in the inner 20” circle from 30 yds. and beyond the better. For me that's the tightest choke I own, a Beretta Full at 0.038 constriction. I also seem to recall that Neil Winston had a thread a while ago and proved that 1 oz. loads, 7 1/2s used from 27 yds. would not result in 100 consecutively broken targets because of thin patterns even though perfectly pointed . I would really like to know what the results would have been with 0.040, 0.045, and 0.050 constrictions.

Am I on base here or out in left field on this stuff?

Cheers

Ron
 

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If you hit the "enter" key twice after a sentence...

You can break that up to read it. Not once, but twice....

Wayne
 

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What Wayne said!

I didn't read much of your headache-inducing post but will tell you that a choke's profile will have a lot to do with how it patterns. A choke of any given measured constriction with a longer parallel section will have a hotter core than one with less parallel. You can't go by designations or even net constriction alone.

Ed
 

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No headache here and a subject that I have long tried to figure out. I agree with AveragEd about parallel section. Try a Pure Gold Extended for proof. But, I shoot a Browning BT99, BT100 and a XT. All with Browning Diamond Grade chokes. The Diamond Grade Full has a restriction of .035 and shoots a pretty dense pattern at 40 yards. All three guns have a "hot zone" about 21" dia. with a full choke. I tried a Briley Extended Full, also a .035 restriction and it was close to worst pattern that I have ever seen. Covered the whole paper with no real hot zone. Why? My other Diamond Grades with lesser constriction have a hot zone of about the same size. Just not as "hot". You really do not gain anything.
 

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Discussion Starter #6
Sorry about the format guys. I cut and pasted from another document and assumed it came across with out change. Guess I was wrong.

Ron
 

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Me thinks you doth think too much! Choke performance is a nebulous thing at best, and pattern performance is affected by many things besides just the amount of constriction of any given choke.
Shot speed, shot hardness, the type of wad used, burning rate of the powder, ad nauseum all have an effect on pattern performance. Velocities of 1200 fps or slightly slower will generally pattern tighter than shells with higher velocities. Shot is subject to damage from tight forcing cones, tight chokes, softness,high velocity, etc, and the more the pellet loses it concentricity, the more likely it is to veer off of a straight line. Chokes that have too much constriction can also damage the pellet and may not produce as tight a pattern as a more open choke.
Then we get to the biggie! shot placement. All the choke in the world will not help a mis-placed barrel on the target.
My advice to you would be to find which choke will best fill a 30 inch circle at the distance you generally break the target. You will probably find one for 16 yard distances and one for handicap.
Keep in mind that the object of the game is nothing more than breaking the target. It does not require you to vaporize it! Consistancy in shot placement is the real key to scoring well, and not how tight the choke will shoot.
As a serious competitor at sporting clays and FITASC, I shoot a fixed choke gun with a constriction of .018 thousandths, and have no difficulty breaking targets out to and beyond 60 yards. Remember that there is always a certain number of pellets that fly straight and true, which make up your core density, and these are the pellets that will do the job when you place the barrel properly for a hit target.
 

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i read an interview with jess briley.
the question to Jess was "after all your research what do you know about chokes and patterns ?"
the answer was "we don't know anything"

enough for me !
 
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