"What chokes are you using?" maybe the most asked question since the birth of the shotgun. There are a variety of theories that are only superceded by the variety of chokes available to the shooter. So to answer this question of questions, I decided to go to the mountain so to speak. I caught up with Cliff Moller of Briley Manufacturing this summer, and sat down and spoke with the man whose is recognized by the industry as the industry leader in this area. Briley makes more chokes for more guns than everybody else put together. The following is the interesting and educational conversation that I had with Cliff.

T: I have always thought that choke work in a shotgun barrel was an unscientific science.

C: It is an unscientific science and I really do not have the slightest idea how it works, and I don't think that any of us knows exactly how it works. There are propositions that it works like fluid dynamics, but that isn't correct. All that I know is that the information that we have is based empirically. We go and do this, we have this kind of constriction or this kind of geometry within the choke, and we shoot them and see the effect. Every time we go to work on specialized chokes whether they are duck chokes or heavy shot chokes, we start at zero and we go in two-thousandths (.002) increments, and we start shooting them until we find something that we like. The problem with this is the multiples of patterns that you have to shoot to come up with something that is statistically reliable. You can shoot ten patterns and in most cases they will follow suit, but there are going to be weird things that happen.

T: So if you were to pattern your shotgun and shoot just one or two patterns through a choke, it wouldn't really tell you a lot?

C: Correct. If you shot ten, you would have better information, if you shot twenty you have a little more confidence in what you have. But if you were talking to a statistician, he would laugh at you, because statistically that is not enough. So we don't know how chokes work, nobody knows what the actual influences are. What we do know is that if we do this, this is the kind of result we are likely to have. You are squeezing a lot of mass through a small area, and it is clustering and moving all around, and pushing around at some fairly high velocities.

T: It would be a lot easier with a single projectile.

C: Sure, you have a multitude of pellets directly and indirectly affecting each other and the dynamics are quite complicated. So how does it work, we don't know. How do we make decisions? Test and try, test and try, test and try.

T: When people talk choke, they talk constrictions, .002, .004, .006, and so on. What do these numbers mean? What is choke and how is it constructed?

C: Within a choke there is a conical area and a parallel area, in most conventional chokes. The conical area is the interface area that is between the actual cylinder bore of the barrel and the choke. We have this interface area to take us from one dimension to the other. In this interface area we need some type of angle to narrow the diameter of the bore. We have tried a radius, we have tried a parabolic shape, and all sorts of different shapes to get a special effect, but a straight angle seems to work the best. There is not enough diameter differential to allow some exotic form to mean anything.

T: I have heard this part of the choke referred to as the "ramp." Is this the correct terminology?

C: You can call it a ramp, we just call it the conical portion of the choke. Now the length of this segment of the choke is critical relative to the diameter of the bore. We like to have a little more that a 3:1 ratio. So if you have a 12 gauge bore which is .730, but let us say 3/4 of an inch. If you multiply .750 inches by three, you come up with 2.25 inches, so we go 2.75. We have found that in a 12 gauge bore that if you go with anything more 2.75, it doesn't offer any improvements. So in a .410 bore we would want at least 1.50 inches in length. If there is not enough choke length then you are forcing the shot together too fast within a given area which leads to undesirable effects like poor distributions and inconsistent patterns. When you look at a pattern, you have a certain area, about 705 square inches in a 12 gauge 30 inch circular pattern, but what you would like to do is magically place each pellet in an equidistant manner, but you can't. What you get in reality is clusters, but what we want is a smooth distribution so that you end up with a minimum amount of holes, or uncovered areas within the pattern. Remember that a 12 gauge 1-1/8 ounce load does not have enough pellets to cover a 30 inch circle for an even one inch spacing between pellets.

T: Is the conical part of the choke the most important part?

C: I don't know if it is the most important part but if it is too short, you get spotty distribution, however if there is not enough parallel area in the choke you get goofy results too. In my opinion you need 5/8 to 3/4 of an inch of parallel to optimize the situation.

T: So the conical portion of the choke squeezes everything down. What's the parallel part do?

C: Takes it out of transition and stabilizes it. Years ago a European gun maker once commented to me that a barrel could look like spaghetti as long as the last four inches are right. I agree with him. The choke is essential in determining whether we have a good barrel or not. The screw choke gives us tremendous flexibility and because it is now a modular component the machining limitations are lifted. We are free to experiment with any geometry we care to investigate. Barrels, on the other hand, are not. For instance, let us say we wanted to experiment with some strange parabolic shape in a choke. Tools would be expensive to make, prone to drifting off center and producing chattering finishes, which would have to be hand polished resulting in totally unpredictable effects. This does not mean that you can't have tremendous fixed choke barrels, you can, and it is just more cost effective and predictable to do the job with screw chokes.

T: So screw chokes are easier to work with.

C: They are easier to work with, and you can do more with them. Most importantly you are not stuck with what you got, based on what game your playing, or what the ammunition manufacturers are going to do tomorrow. They give us more options. Now on the negative end of screw chokes is the geometry. On the conical side of the choke there must be some clearance at the back so that where it seats up against the barrel there will be no interference with the shot load. This clearance is called the minimal gap. The larger the clearance the less precise you have to be putting the choke in straight. But the larger the clearance also means more plastic build up, which is a total mess, and the less ability you have to make small changes. You get a "jugging" effect that reduces resolution, which means you can make "big" changes but you lack the ability to the fine tuning changes. For instance I can take a choke that has a minimal gap and change the constriction by .002 to .003 and see a change. But if I have one that has a massive amount of clearance in back then I have to go to some extreme restrictive differences to see some changes.

T: So what should skeet shooters look for in their chokes?

C: That is a tough question. What do we sell the most? The answer is .005 and .006 across the board. That's what I would blindly recommend to anybody. That's what I shoot. But there are a lot of other considerations. If you load one shell at a time, what the hell does a shooter need a .006 choke in the top barrel for, when none of your second shots on doubles when shooting a regular round of skeet, is further than 15 yards? You don't. A .003 or .004 would be absolutely fantastic.

T: I shoot a .006 in my top barrel for regular skeet, and that's my open choke. Maybe I should go to a .004?

C: You're just fine. Anyway, there are so many variables when looking for the perfect choke. Is the target coming at you or is it going away from you? What is the presentation of the target? One thing that gives a lot of credibility to tighter chokes in skeet is that we shoot a lot of edge on targets.

T: Meaning that a High 4 would require more density to be broken than say a High 8 because of target profile.

C: Correctomundo. But nobody out there has told us how much kinetic energy it takes to break a target. Are you shooting the belly of the target or the edge? The cross section or wall thickness of the target affects how much energy it takes to break that target. Is the target coming or going, how much spin does it have, are you breaking it over there or over here? Are you shooting doubles like Dr. (Jim) Biddle or like Todd Bender? Doc better have a bad ass choke way out here, Todd Bender doesn't need it. The way that we dissect a pattern is to divide it into three equal areas. These equal areas consists of three concentric circles with areas of 235, 470 and 705 square inches, and each circle has a diameter of 17, 22 and 30 inches respectively. The center area is a greedy sucker. I like to metaphorically compare it to our solar system where the sun, through gravity, has kept all the orbits of the heavy density planets nice and close as opposes to the gaseous planets, which have orbits of greater distance. The center will eventually give up but by this time that is useless because velocity will have been lost. The tough part is getting shot and distribution in the third area, because as a rule, areas one and two don't give shot up. So we are constantly looking for a balance of density and pattern size. Factoring in our own personal ability complicates the equation. Perfect example, Mike Schmidt comes in here with a .720 bore 12 gauge barrel, and what we know about bores (small bores versus larger bores) is that small bores are very difficult to get open patterns out of. You can get modified or improved cylinder out of them, but if you have .720 Beretta like Schmidt has, you can't even get a cylinder out of it. You can't. It's super tight. On a big bore .735 or .740 we can get the most beautiful open choke, but we have to work really hard to get a tight choke out of it.

T: Okay, so I was just back there in the shop talking with Mike, and he's shooting a .720 but going tighter!

C: Because he is trying to find the balance between his equipment and his personality. Mike told me once, you ought to go out there and just practice with a modified choke. It doesn't cost you but one or two targets and it will improve you. Well it didn't cost me one or two targets. It cost me five or six targets.

T: His equation of equipment, personality and ability is different than yours.

C: Absolutely. He has the target and sighting resolution that ninety-eight percent of the time he is in the center. The tight choke does nothing but increase his confidence. But for me a tighter choke works the opposite way because it causes me to miss a lot more and lose confidence. This is subjective of course, but guys like Mike and you, and Wayne are working in the inner circle. The rest of us aren't that precise, we need the second and third areas. So making a decision about chokes is all about balance.

T: How much does ammunition come into play within the equation?

C: A lot. Let's talk about the .410 ammunition available today from Federal, Winchester and Remington. They all have different velocities. For Federal .410s, we recommend nothing less than .006 restriction, Winchester .005 to .006 restriction. With Remington's, .003 to .004 is plenty, but your welcome to try .006 or more if smoke is your objective. Look how many times we have seen ammunition change. As far as ballistics are concerned, the 28 gauge is such a sweetheart in terms of choking, it really does not require a whole lot, but in the past we have constantly change our approach based on what the ammunition manufacturers were doing from year to year.

T: So a customer calls Briley, wants a tube set but really does not know what chokes he or she should have, and asks, "Hey guys, what do you think." It's going to be the .005.

C: Given our experience that is the best choice. In the small gauges we look at 26 inch circles and we would like to have 95 percent of the shot within that area. We know that within that circle there will not be perfect distribution, sometimes it's better, sometimes its not. I have never seen a pattern with perfect distribution ever in my life. In reality with the .410 we are living in an 18 inch universe. Now I do not recommend that everybody tighten up and put everything, 100 percent, into that 18 inch area, because you have to be damn good to be able to handle that. So again it's all about balance. You have a great range of shooters from Dr. Biddle to Mike Schmidt, and they are two extremes. Biddle does not believe in super tight chokes, but in doubles he puts a son-of-a-gun in that top barrel.

T: What's he shoot?

C: I don't know, I sell him everything we have. (laughs) I am sure that he shoots at least a .012 on that second barrel. He would be foolish not to go .012 on the second barrel because of the distance that he shoots his second target at Station 4.

T: When I do any patterning I shoot a choke at 14, 20 and 24 yards. Fourteen yards is about the distance that I shoot High 2; most of my targets at 3, 4, and 5 are shot from 17 to 20 yards; and then I have paced off my second shot at 4 and found that I break it at about 24 yards. I have found that a choke that looks good at 14 to 20 yards may start to fall apart at 24, so that's why Doc and I choke down in doubles.

C: Definitely, you need to choke for how you are shooting, nothing else.

T: Now I also wanted to talk about shot string, but let me run this by you first. I've always thought that no matter what choke or gauge or length of shot string you are shooting, that with a target going 50 mph one way and a shot charge going 1200 fps another way, that intersection of both elements was only dependent on whether you were in the right place or not. Pattern, gauge, none of it mattered except that you pulled the trigger in the right spot at the right time.

C: Bob Brister did some work years ago on shot strings, and as close as I can tell, shot string is not really meaningful. I believe the length of the shot column may be somewhere in the neighborhood of 5 to 8 feet long at 21 yards. But if you do the math, even if you consider the string to be 16 feet long, the shot is moving so fast in relationship to the target that although it may be relevant to some people, the numbers aren't there to support its significance. There are some that believe that by going to a tighter choke or by swinging the gun faster, of course you better be talking real fast-that you theoretically lengthen the shot string. If in his mind those small numbers are enhanced in his favor then...

T: Then have at it buddy!

C: Right. Then yeah, OK that's fine, but you have to make the decision. Does that mean something or not? I don't know. I think it is meaningless because all of the variables involved. The information is not there to support it.

T: I think that it is interesting, for the first time in my career, that I have yet to pattern my tube set. They're your tubes and I took them out, shot them on day one, and three years later, still haven't found a need to go pattern them. When I shot them for the first time, I got the breaks I wanted, I hit a lot of them, didn't miss any, so screw it, I don't want to pattern them.

C: You don't want to know. As long as you have confidence, that's the goal.

T: Something that is new to me is the rifling in my tubes. So how about it, is rifling in tubes a major advantage?

C: The first time we experimented with it, Hastings was rifling some shotgun barrels, straight rifled barrels. They said that it brought the flyers in. So I said great, and what we found out when we did testing with rifling, is that you had, in a high percentage of the instances, flyers that were brought into the outer area. You are not bringing them into the center, but into the outer ring, and not all the time. Were they always brought in? Hell no. So with rifling in our tubes we are trying to bring the excellence out to the next decimal place.

T: So that might be worth a target or two a year.

C: Maybe, or one or tow per tournament. We may be talking about something very minimal like 10 or 12 pellets with the .410. But we will take it. Now, can you accomplish the same thing by making the pattern smaller with tighter chokes? Yes, but we go back to those three circles. The guy in the center is greedy, he takes too much. The only way we can get him to give up pellets is with less constriction, rifling allows us to add to the outer rings without altering the balance between the three circles in a negative way. Now on the subject of rifling, we are very concerned with steel shot. From a choke control standpoint steel by nature shoots very tight. We made experimental tubes with twist rifling for small gauge steel, and I could scatter the hell out that steel shot with the twist rifling. But the control that we have over lead wasn't there. We just don't have a lot of control with steel, at least not to the degree as we do with lead. It seems that there is a nominal area that steel operates in, and we are continuing to look for ways to improve the control of steel shot.

T: Earlier you mentioned plastic build up in chokes. We talked about the clearance that creates this monster, but what should you do about it and how often?

C: Let's go back to the fixed choke days. Earl Barroso many years ago asked Jess, "How do I clean these tubes?" And Jess replied, "Every time you put a shell through them you clean 'em." So he never cleaned them. But these days what you want to make sure that when you see buildup you are affecting your choke. You are changing the dimensions and the way they shoot. A critical thing about choke is concentricity. Everything needs to be in line and totally round. That's why a lot of products that we use, we make sure that the materials do not deform under heat treating or machined after heat treating. When you start letting plastic buildup define the geometry of your choke, you are making a mistake. Now I don't recommend cleaning your chokes every time you shoot, but at least once a month.

T: We talked earlier about over-boring and its effect on patterning. What else is there to over-boring?

C: Over-boring is definitely a good thing. You get better distribution, less recoil, and you get more open patterns, and for most of us that is a good thing. Overall, over-bored barrels just give better performance. In tube sets or the smaller gauges, the results are minimal. Anytime that I have over-bored small gauges, quite frankly I cannot see much of a difference. Right now we like what we see with the .415 to .420 bore diameters with the .410.

T: Is over-boring as effective or more so in reducing recoil than porting?

C: They are both effective. The recoil effect that porting has is more linked to a reduction in muzzle jump that is perceived as recoil. I would say the over-boring is more meaningful when talking about recoil reduction. There are four things that you can do to reduce recoil. Number one, have a great piece of wood, meaning a stock that fits you. That's first. Then there is over-boring, porting, and lengthening the forcing cones, in that order.

T: Back to chokes, I visited Krieghoff last year, and was shocked to see a collection of screw in chokes that were ripped open like someone had taken a can opener to them. I was informed that the barrel or the chokes themselves had been dropped, or somehow gotten out of round, but then still shot, and this was the result. What kind of care should we give additional chokes that are not kept in the gun?

C: If you drop them, inspect the lip where the choke seats up to the barrel. Look for concentricity, use your fingers feel the nicks. Number two make sure that they are tight when in the gun. Sometimes with damaged or loose chokes, you will get interference from blowback. This is gas that gets in between the choke and barrel. When a gap occurs, that choke can be ripped in half. So keep'em tight, keep'em clean.

T: What about putting grease on a choke when it is inserted into the barrel?

C: What grease on a choke does is that it closes the gap between he barrel and the choke absorbing some of the blowback. It also acts as a lubricant which makes it easier to clean and get out. If you don't clean them regularly they can become rather difficult to remove from the tube, and in some cases embedded.

T: Right now, I cannot get my 20 gauge bottom barrel choke out.

C: Let's take it out right now.

T: I don't want it out. I like it. It's perfect.

C: Well then just leave it in, fool. Have you been listening? Although you can track Cliff down at most all of the major tournaments, while at Briley Manufacturing that can be tough. He is usually in the back somewhere testing and trying, testing and trying, testing and trying. However Briley's full staff of sales and technical representatives are always available to answer any questions about your shotgun, rifle or pistol needs. Please give them a call at 800.331.5718.

Todd Bender is an Honorary Fellow in England's Institute of Clay Shooting Instructors, and he is a Briley shooter. For information on the BenderShima Shooting Clinics or for information about private work with Todd call 678.296.5184. For Todd's videos on skeet shooting call Sunrise Productions at 800.862.6399.