Choke Chooser™

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Beretta Chokes

Dear Technoid,

In one of your many musings, you stated that the true meaning of life could be found in the selection of chokes (or something to that effect.) In my own quest, I stumbled across a little tidbit in the latest Beretta catalog. It seems that a Beretta skeet choke, called a “Skeet Beretta,” actually has a negative constriction. (Is that an oxymoron?)

Given that you are the proud owner of a Beretta gun and have all of the appropriate Technoid measuring tools, is this really the case? And does this mean I need to talk to Briley about getting not only a Light Modified but also a Skeet to fill out the “Technoid Choke Trio”? (Full after 35, Skeet at less than 20, and Light Modified for everything in between.) One the otherhand, given the chokes that came with the Beretta, is it possible to define a “Beretta Bunch?”


Dear Logan,

Rule #1 in chokes: Measure! As I have said ad infinitem (ad nauseum?), just because some choke tube is stamped with something doesn’t mean that’s what it is. True, Beretta is slightly more accurate than the generally grossly mislabled Browning Invector screw chokes, but only slightly.

Naturally, choke depends on resultant pattern, not on constriction (more Technoid archives), but let’s just pretend that everyone follows Briley’s lead on screw choke constrictions and has:

Cyl = .000″
Sk (or Sk 1) = .005″
IC = .010″
L. Mod (or Sk 2) = .015″
Mod = .020″
I. Mod = .025″
L. Full = .030″
Full = .035″
X Full = .040″

The Beretta sporters come with Sk, IC, Mod and Full. No, they don’t necessarily measure .005″, .010″, .020″ and .035″ constriction, but they do make a try at it. If you mike enough Beretta chokes at the gun shop, I am sure that you can find some that will measure out. Briley is sometimes even closer than Beretta, sometimes not. I have two Briley L. Mods. One an ID of .711″ for .011″ constriction in my .722″ bore 390 and the other is dead on at .015″ constriction.

In one of my 303s, I also had two Cyl chokes, one a Beretta factory and one a Briley 2X extended. The Beretta factory Cylinder Bore choke threw the usual pattern. The Briley 2X Cylinder Bore choke threw the most open pattern I have ever seen from a shotgun. It was like a spreader. I have never seen anything like it.

There are a number of approaches you can take. One is to just shoot what you have, not measure anything and have faith. It makes life simple. Second is to actually borrow a bore mike (Baker’s is the best) and find out what you have. Briley can fill in any gaps. Just measure the exact bore size and then tell them how many points of constriction you want. They will send you back something just about dead on.

Thirdly, you can actually do the patterning with the shell that you are going to use in competition. At 40 yards, using a 30″ circle, you will want your skeet choke to put 45% of its pattern of #9s into the circle. Your L. Mod should put 55% of its load of #8s into the ring. Your Full should put at least 75% of its # 7 1/2s into the circle.

As an aside, there is no such a thing as too full a full choke. An edge on bird at 35-40 yards cannot be broken “reliably” with anything less. The trap shooters have understood this from the beginning. Sporting clays shooters shouldn’t have to relearn it.

Now, as to the Beretta “negative” skeet choke: I have fooled around with Beretta skeet guns on and off since the 680 some 20 years ago. Beretta solid skeet chokes are all over the place. I have seen them with up to .010″ constriction and I have seen them with none. Generally, most of the Beretta solid choke skeet guns that I measured back in the ’80s when I was doing a lot of that had cylinder bore barrels right out to a flare at the muzzle. The muzzles weren’t jugged as they do for screw chokes or Tula chokes, they were just beveled to a flare on the inside last 1/4″ of the barrel. I haven’t tested the “cylinder to a flair” skeet choke with the new tiny ISU 24 gram loads, but they worked really well with the old 32 gram 4 dram stompers we used to use. Ennio Falco seemed to like those chokes when he used a Beretta to take the Olympic skeet Gold at Atlanta last go around, but you never know what he really had in the front of his gun.

Still, if I only wanted to use three chokes for sporting to match with the three shells and three distances, I would go with .005″, .015″ and .035″. If you decided on .000″, .015″ and .040″ I couldn’t argue too much either. You may have to get the L.Mod .015″ and the XFull .040″ from Briley as Beretta doesn’t make chokes of those designations (though you can’t tell what you will get until you measure).

One final note before the coffee runs out- Just because you CAN shoot sporting with only three chokes and three shells at three distances, doesn’t mean that I personally always do it. In a single barrel auto like the 303 or 390, I do most of my FITASC shooting with a .020″ Modified, and I did save that wall-covering Briley 2X Cylinder bore for those stupid 5 yard shots you get every now and then. As the Technoid, it is my duty to do things that are unnecesarily complicated. You are permitted to be smarter.

Best regards,

Bruce Buck
Shotgun Report’s Technoid
(Often in error, never in doubt.)

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Altitude and Patterns


My question, which I don’t think you have addressed before (if that is possible), is the effect of altitude on choke and shot size selection.

I currently shoot sporting clays at a club where the course ranges in altitude between 2,500 and 3,000 ft. When I first moved here from the flatlands, I noticed that I seemed to be breaking birds with less choke and smaller shot size than my previous experience. I realize this is purely anecdotal. I don’t know for sure even how far the targets are, how may pellets were hitting the targets, let alone how much energy they were carrying.

Last year one of our members, who likes to pattern his shotguns, posted some limited data that the same shotgun with the same chokes and shells patterned at least one choke size tighter at our club than they did in Florida.

What does the science tell us about this?

Dear Stephen,

In school I slept through most of science class. They weren’t getting into shooting anyway. But I have learned a lot about how altitude affects patterns by listening to shooters who know a heck of a lot more than I do.

Shotgun pellets are affected by the density of the air they are shot through. Sounds pretty simple. The denser the air, the more the shotgun pattern opens up. Air at high altitude is less dense than air at sea level so patterns shot at high altitude will be tighter. This was certainly the case during the 1968 Olympics held in Mexico City, which has an altitude of over 7,500 feet. Shooters were told to open their chokes to compensate for the altitude. Many people have found that a choke which produces a modified pattern at sea level will shoot a full pattern at a significant altitude.

Other things affect air density which will affect the shotgun’s pattern too. In warm weather the pattern will be tighter than in cold because cold air is denser than warm. It’s the same with dry air being denser than humid air (though this seems illogical, that’s what Mr. Science mumbles to me).

So a hot, humid day at altitude will give you the tightest pattern, while a cold dry day at the seashore will give you your most open pattern due to the denser air. Thinner air means tighter patterns.

Now, instead of just worrying about chokes and shells affecting your pattern, you have to worry about the weather and altitude. Who said shooting was easy?

Best regards,
Bruce Buck
Shotgun Report’s Technoid

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Comb Adjustment Formula

Dear Technoid,

I once read about a simple rule of thumb how to calculate the effect of changes in comb height to changes in point of impact: 1/16 inch on the comb would make 1 inch on 16 yards. Do you have any idea on which formula this calculation is based? What would the change be on 32 yards? Surely, such a formula needs to take barrel length and length of comb into calculation (i.e. distance from the eye to target)? Can you enlighten me on this subject?

Best wishes

Dear Anders,

I first heard this formula from Paul Smith, the English instructor and fitter at Griffin and Howe. If it is 1″ at 16 yards, it would be 2″ at 32. The formula is based on simple triangulation (simple for you, not simple for me- I’m a verbal type and rely on people far smarter than me to do the numbers crunching).

To me 1/16″ at the comb seems like a whole lot, but when you think of it, it would be around 2.5″ at 40 yards. Since a 24″ killing pattern at 40 yards would be exceptionally large, 2.5″ is a pretty high percentage shift.

They use the distance at 16 yards, rather than at 40, because you get a much more clear cut pellet strike at 16 than at 40. This makes accurate measurement far easier. If you have screw chokes, always do your point of impact testing with Full choke for this reason.

The distance from th eye to the front bead should be an important number to calculate the shift, but frankly, shotgun isn’t all that precise. My guess is that you are in the ballpark for anything with a standing breech and 28″ or 30″ bbls. If the Brits really did originate this formula they probably just assume that everyone uses a 30″ SxS English Best.

Best regards,

Bruce Buck
Shotgun Report’s Technoid
(Often in error, never in doubt.)

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Hard Kicking 686

Dear Technoid,

Just bought a Beretta Silver Pigeon trap gun, 12 ga. Comes up to my shoulder like it was custom made for me. But it’s also going to break my shoulder if I don’t find a way to reduce the recoil.

Yes, I know I can reduce my reloads, but I don’t want to set up a second reloading station, and my present one is just right for shoulder-kindly skeet loads (used in my Citori)

I called a place in Houston and they said I should have the gun ported and the forcing cones reduced. Having read a number of articles in your magazine, I am aware that you don’t think much of porting (especially for single-shot trap) and that Beretta gives longer forcing cones anyway.

My local dealer wants to install mercury-filled recoil reducers in the stock (and he thinks I need two). Having removed the butt pad from my 686, I see a yawning cavity that looks like it’s ready for not two but three cylindrical reducers.

I don’t want to knock the dealer who sold me the gun, but I’m not sure he knows the full story on recoil.

What would you do with a Beretta 686 that kicks like a horse but gave me good scores the first time I tried it on trap?



Dear David,

The first question is whether it kicks you in the face, in the shoulder or both. Facial kick is due to poor gun fit. Kick in the shoulder is just plain pure old recoil. No amount of porting or recoil reducers in the world will help if you are taking it in the chops instead of the shoulder.

Trap shooters are the experts on recoil. Trap involves a large number of rounds, little body movement and full power loads. When you go out to the Grand, you will see that virtually each and everyone of the vendors sells something to reduce recoil.

While I definitely don’t think much of the machine shop’s Holy Grail of coning, backboring and porting, I must admit that the full Ballistics package did reduce recoil on the Beretta 303 bbl I tried. It didn’t reduce it much, it took too much weight out of the barrel and it can cause reliability problems with certain shells in an auto, but the full Ballistics package definitely, positively did reduce recoil a tiny bit. We swapped bbls back and for on my stock 303 and there was a slight difference. Was it worth it? I don’t think so. It certainly wouldn’t turn a kicker into a coddler, it costs a ton and it makes the barrels quite a bit lighter (which you may, or may not want). I have been even less impressed by the barrel “packages” from other shops.

Adding weight to the gun is the blunt approach, but it always works. Each percent of weight that you add to the gun will reduce recoil more or less by that same percent. I think that your local dealer was right. A heavy stock doesn’t matter much in a trap gun because it is shot mounted. You get two 10 oz mercury reducers ( or just plain 20 oz of lead- works just about as well) and your recoil on an 8# gun should drop 14% when it hits 9.25#. 14% isn’t the world and may not make the gun shootable for you, but it is about twice as much recoil reduction as I felt from the Ballistics barrel work.

You might try pulling off your recoil pad and filling that giant hole in the back with 2# of lead. That alone will reduce free recoil by 20%. See if it makes enough difference to matter. If it does, then go for the reducers.

Also, don’t forget a good recoil pad. For trap I like Kickeez and Terminator best, with the edge to the Terminator for the mounted gun games.

One alternative that really does work is the pneumatic stock as made by G Square and the others. That really does tame recoil in the mounted gun games, though it doesn’t help much in low gun games because it depends so much on a firm and repeated shoulder mount.

In spite of the fact that you want to leave your reloader set up for your skeet load, since you have to change shot size when you reload for trap (unless you use #8 for everything, which is OK) it should only take you a moment longer to drop in a smaller powder bushing and one oz shot bushing. Reducing your shot load from 1 1/8 oz to 1 oz at the same velocity will lower recoil 19%. Combine that with the 2 pounds of lead in the stock and you will have a soft shooting (if smaller patterned and butt heavy) gun.

One final question: Are you sure that recoil isn’t gun fit? Your Citori doesn’t kick you and the Beretta does. They both weigh about the same. That means that they both recoil the same. Yet one hurts and the other doesn’t. Sounds like gun fit to me.

Best regards,

Bruce Buck
Shotgun Report’s Technoid
(Often in error, never in doubt.)

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Ammunition Shortage-Federal Podcast

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Extended Chokes=Increased Barrel Length?

Dear Technoid,

I have no idea how to ask this question in order for it to make sense but if anyone can figure it out, you, the Technoid can.

My favorite and frequent shooting partner has an older Perazzi. It wasn’t really a sporting gun when introduced but a really heavy field gun that he uses for Sporting. Something with a 5 or maybe a 3 in the model name. Somebody turned him on to Mueller chokes which are just fine and all that. They look like they stick out 3 inches, visually turning his 30 inch barrels into 33 inch barrels. My F3 has Mueller’s and they stick out nearly 2 inches. I have to use a longer than normal case for the 32 inch plus Mueller chokes.

What I am trying to ask is what is the visual difference in a 30 inch barrel with 2 inch chokes and a 32 inch barrel with flush or fixed chokes? If you can, forget the weight differential, handling like a pig on a shovel, thing. Could not barrel length increases, at least visually if not ounce for ounce, be attained by the ingenuity of a choke maker?

Thanks again.


Dear Steve,

As I understand it, you want to know if extended chokes increase the visual barrel length? I’m assuming that you mean increased barrel length affecting sight picture on a target lead.

My cogitated answer is “Yes” and “No”. Well, sorta. Here’s what I mean.

I’m a hunter and ex-international skeet shooter, so I shoot sporting and skeet with a dismounted low gun. I sort of cheat and put the butt under my armpit so that I have to push the barrel towards the target as I raise it. This gets my body into the motion of the target and keeps my weight slightly forward. When you shoot with a slightly lowered gun like this, longer chokes do visually extend the muzzzle and do affect the sight picture as the gun is being raised.

BUT… if you start with a premounted gun, then you are looking right down the barrel and barrel length really can’t affect sight picture or lead on the target. It’s like putting your face down on a road. You can’t tell how long the road is with your eye right down on it. But stand up so that your eye is above the road and you can get an idea of its length. Same with the gun. When premounted, even with a very slightly high stock showing a little bit of the rib, you can’t tell how long the barrel is.

That’s why I believe that barrel length is really more a question of weight and balance than visual sight picture if you shoot premounted.

Muller chokes? Jimmy Muller and I lived in the same town in Connecticut when he was starting out 20 years ago and I knew him pretty well. He made parts for airplanes and definitely knew his alloys. Those are good chokes.

Best regards,
Bruce Buck
Shotgun Report’s Technoid

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Reading Breaks


I have been shooting skeet for a number of years and do ok at it…..well enough to keep trying anyway. I have often seen a target obviously broken toward the front or the rear and heard a comment from someone that the shot was either in front or behind, i.e. a comment on the lead.

I’ve made those comments myself too. But the more I think about it the less certain I am that we can tell. If you hold an edge-on target against a random test pattern from the patterning board, it seems obvious that there are many locations throughout the pattern where a hit on the front or the rear of the target could occur. I know it is occasionally possible, under perfect lighting conditions, to see the shot string in the air; but that doesn’t occur often for most of us.

I also believe we can usually distinguish a well centered target from one that has been fringed. But when a target has been fringed and only a few pieces come off of the front or the rear, can I really count on the bulk of the pattern having been in front of or behind the target.

Maybe this is a case of probabilities….What think ye?


Dear Don,

I really don’t know what to think, now that I think of it. Like you, I had always assumed that when you blow the front of the target off, that you were a bit in front. One of the reasons that I shoot slightly tighter chokes than most people do is so that I can “read” my breaks. I have heard many other better shooters tell me that this is why they shoot full choke at 16 yard ATA trap.

When shooting skeet with my Beretta 303, I have always obtained my best scores using a measured .010″ choke. This is a bit tighter than most people use for skeet, but I really can read my breaks. I can definitely see that I am in front when I take the nose off the bird and I can take corrective action or just back in the glow of another job well done. The break just confirms what I have already realized.

I have fooled around a lot with cylinder bore at skeet, but find that I am frustrated by the inability to achieve a harder break when I know that I am dead center. Consciously or unconsciously, I seem to need to read my breaks.

When I fringe a target and a piece comes off, say, the front, I still consider that pretty good feed back. Since I am on the fringe, if the front-of-the-target side of the pattern is barely good enough to pull off a piece, it stands to reason that the rear, 5″ further to the edge of the pattern, is less likely to produce a hit. It can happen, as you suggest, but it is rare enough so that I can ignore it- just as I ignore my bad scores and seem to remember only my better ones.

Bottom line: breaks and patterns are random events, but not all THAT random. Occasionally you will get the wrong information by reading a fringe break, but generally it tells the truth. At least, that is my take on it.

Best regards,

Bruce Buck
Shotgun Report’s Technoid
(Often in error, never in doubt.)

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TGS-What I’ve Learned From Reviewing Shotguns

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Browning vs. Beretta

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Ask the Instructor: Where To Look

Source: Ask the Instructor: Where To Look

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