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Discussion Starter #1
Noob to purchasing new chokes here...

I have a SKB 85TSS and while looking at various websites, some refer to cylinder size and others to constriction. For instance, on the actual SKB site they vary from .000 to .035 respectively. However looking at Carlson's, for example they refer to Diameters of .695-.735. Are these just polar opposite ways of measuring the same thing? I can't get the math to work out that way when looking at a certain size...

SKB Mod: .020
Carlson Mod: .715
Others go by a %...
 

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To really understand the choke designations, you should know the bore diameter of your particular shotgun. Your first set of numbers i.e.. .000 to .035 indicate how much the individual choke tubes constricts your bore diameter. The second set of numbers i.e. .695 - .735 indicate the actual bore diameter of the choke. If you knew the bore diameter of the barrel, you would simply subtract the bore diameter of the choke tube from the bore diameter of the shotgun barrel and you would come up numbers similar to the .000 to .035
Check out the Briley choke tube website to get further info on this.
John
 

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Discussion Starter #4
Go to Trulock chokes, FAQ.

First Class, all the way!
I spoke with the manufacturer at SKB and they recommended Staying with the Briley Competition Series. I checked out the website and was considering the IM with the (probably just marketing) ported model. Anyone have any experience with them?
---Also, does the black oxide do anything, or cosmetic? ($5 extra)
 

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This website shows your barrel's bore to be .735 inches.

SKB Shotguns: 85TSS Barrel Specs

So a .020 choke means it restricts the opening by .020", making the exit diameter .715.

Chokes are normally .000 (CYL), .005 (SKT), .010 (IC), .015 LM, .020 MOD, and .025 IM, etc... to get the tighter constriction. Since IM is usually .025, so it should reduce your .735 bore diameter to .710.

In theory, it should put about 60% of the shot into a 30" circle at 40 yards.

 

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Discussion Starter #6
Hey thanks for making the math work out for me. It finally makes sense-bore/constriction.
So then I have to take it a step farther and ask the formula to figure the 60% @ 40.. :)
 

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I would forget about the percentages at 40 yards. It is out dated and not accurate any more. The percentages were calculated when every one loaded shotgun shells with over powder cards, filler wads made of felt or card board and no shot cup. With modern ammo it is now up to you to find out what your ammo and chokes pattern.

If you are shooting Trap: Singles, Handicap and Doubles I would suggest you pick up an IC for 1st shot in Doubles, IM for Singles and 2nd shot Doubles and a Full choke for Handicap.

You can then pattern with the chokes and ammo, at the estimated distance you plan to shoot the targets and analyze the patterns. Or you can just start to shooting and analyze if you get really good breaks if you point the gun right.

Jason
 

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Waverider is right, percentages vary a lot dependung on many factors, especially the ammo you shoot. If you really want to see how it shoots, hang up some paper and shoot it with different chokes and ammo. Harder shot (quality ammo) will keep a tighter and more consistent pattern due to less shot deformation. Also, some guns / chokes show very little pattern difference between IM and FULL chokes. Give it a shot and see what ya get.
 

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Hey thanks for making the math work out for me. It finally makes sense-bore/constriction.
So then I have to take it a step farther and ask the formula to figure the 60% @ 40.. :)
Trigger, using "percent high" is a poor way of determining what's going on because it means different things to different people and nobody can agree, so it is meaningless.

Better to pattern your gun at 40 yards and say "the center of the pattern is XX inches above the point of aim at 40 yards." That makes sense.

Better yet, find Neil Winston's posts about patterning at 13 yards.

Tim
 

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Improved Modified is a good selection for use out to 25 yards - others will have opinions/experience to consider. Extended tubes of whatever color are desirable - helps installing and keeping chokes tight. Forget ported extended chokes - just a sales gimmick with no advantage BUT with a DISTINCT disadvantage of trying to keep them clean. Regards, Ed
 

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Trigger71,
I purchased a used (like new) 85TSS combo last December. Did a lot of research on the gun before buying. Briley developed and manufactures the "Competition Choke System" for SKB. I have not done any pattern work other than the 13 yard POI check when I was setting up the gun. I have found that I get my best results from both the 16 yard line and the 22 yard line with the Improved Modified extended choke. I'm defining "best results" as best scores with consistent solid breaks. You can purchase the Competion Extended chokes directly from SKB for $35 each or buy them from Briley for $45 each. They are the exact same chokes. Also, SKB calls the .030 choke "Full" and the .035 choke "Trap Full" whereas most other choke manufacturers would label them "Light Full" and "Full". Personally, I feel no need to try any of the more expensive Briley offerings such as the black oxide, spectrum or ported versions. I am certain you will love the gun as it provides many of the features of much more expensive brands and is built like a tank. One caveat however: the early versions of this model had weak hammer springs which will break at the bend after extensive use. It is my understanding that SKB has addressed this but you may want to keep a few replacements on hand just in case. Enjoy your gun and break 'em all!
Denny
 

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Discussion Starter #12
Trigger, using "percent high" is a poor way of determining what's going on because it means different things to different people and nobody can agree, so it is meaningless.

Better to pattern your gun at 40 yards and say "the center of the pattern is XX inches above the point of aim at 40 yards." That makes sense.

Better yet, find Neil Winston's posts about patterning at 13 yards.

Tim

Ok, just read the Winston 13 yard post. lol, I may be more confused than before. However, there are tons of related posts in regards to it...looks like I'll be up late tonight! thanks for the info
 

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Don't rush into anything until you are clear on choke constriction. Read Neil's post on patterning at 13 yards again and again if necessary. Take your time before spending your $$$$.
 
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If you want to shoot all the games-----Its simple just buy a full set of all 5 choke sizes and your good to go. Remember 2 sk. if you want to go that route, Briley sells there bulk choke packages at a discount. Now if its just trap get a mod. , a Improved mod. and a full and your good to go. For singles start with the IM and then try the Mod. Shoot both for a month or so and then get your ave's for each. Then you'll know what works best for you.

Now I say get the extended chokes. I have the Black Oxide chokes and they are fine, but I'm not sure its worth extra money for them. The plain Stainless Steel will do just fine. But remember chokes can be like Jewelry and add to the look of whatever gun you have. While the bling will not get you extra targets, You'll look good at the range while you miss. Bottom line is all of Briley's extended chokes are just fine. I'd stay away from the ported chokes, and having to spend extra money for nothing. The speed wrench is worth the money if you like all 3 games and can come with the package deal. Break em all Jeff
 

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Experiment, my Fabarm, with a . 015 , lgt mod. breaks birds in lots of pieces all the way back, why ?? no idea, so the pattern board is your friend, l use a monopod to see what pattern I'm getting, your going to shoot well cause your doing your homework.... I know shooters that have no idea where their gun shoots !!!
 

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Discussion Starter #16
This website shows your barrel's bore to be .735 inches.

SKB Shotguns: 85TSS Barrel Specs

So a .020 choke means it restricts the opening by .020", making the exit diameter .715.

Chokes are normally .000 (CYL), .005 (SKT), .010 (IC), .015 LM, .020 MOD, and .025 IM, etc... to get the tighter constriction. Since IM is usually .025, so it should reduce your .735 bore diameter to .710.

In theory, it should put about 60% of the shot into a 30" circle at 40 yards.

Thanks again Dallas! I keep referring back to this post for help. I did talk with SKB and found the source of confusion. In 2008 they eliminated what they called, "Extra Full" and then renamed the chokes going forward accordingly.

SKB email: "Please see attached conversion chart, the changes were made back in about 2008.
This change was made to align the SKB nomenclature and constrictions closer to the industry standards for choke tubes."

So what I've learned is: Ignore names between chokes and brands of chokes. Go by numbers. Measure choke, subtract from my bore size (2003 85TSS .735) to find constriction. Pattern the choke, move up or down accordingly based on numbers not names. Would you agree?

So I've got the math to work out, but having a hard time measuring the chokes to coincide. Where do I place my micrometer to measure? Learning more each day on this forum, Thanks!
 

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No disrespect intended Trigger71, but why are you measuring chokes? Are you considering buying chokes that are not marked either with constriction or bore, but only IM, M, F, etc.? Or do you have unmarked chokes that you are trying to identify? The reason I ask is because if you buy, for example, the SKB Competition Extended chokes, either from SKB or Briley, they have already done the math for you and the chokes will be marked accordingly.
 

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Thanks for the kind words Trigger. The numbers help, but the shot pattern on a pattern board will be the most telling to determine what pattern you really have. Different ammo patterns differently, too.
 

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Discussion Starter #19
Or do you have unmarked chokes that you are trying to identify? The reason I ask is because if you buy, for example, the SKB Competition Extended chokes, either from SKB or Briley, they have already done the math for you and the chokes will be marked accordingly.
No worries Denny,
Yes, I bought the gun with a variety of flush/extended factory chokes. Some had bore data, a few names, and a couple with slots. Until I got the SKB info of the change in 2008, nothing jived. It appeared I had some of both era's --I got out my micrometer and that made things worse.:3schild48: All ducks in a row now and I've relabeled them all with numbers.
--That said, I am missing what I wanted, a 0.030. I see SKB site has them for half the price of the Briley site; do you know if they are any different? (Excluding the cosmetic and or ported Briley offers)
 
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