In general, I stick with the same chokes for all the gauges at the same distances (except the .410).
In general, your comparisons of manufacturer's dimensions are correct (and I prefer Trulock and Carlson tubes/constrictions). Others swear by Briley.

And I can break as many sporting clays with 3/4 oz. of 8 1/2s in my 28 ga. as I can with 7/8 oz. of 8s in my 20 ga. or 1 oz. of 7 1/2s in my 12 ga. The reason for this is quite simple - check the pellet count for each of these loads in any reloading manual, and you will find out that the lighter loads of smaller shot each have a few pellets more than the larger shot but heavier load.

These lighter loads (mine are usually all handloads) break clays equally well.

I would suggest that you pattern the chokes and loads at the distances of 20, 30, and 40 yards. Do it with different shot sizes, as well. You will learn a lot.

One caveat - for clay targets, you just need a dense enough pattern of shot to break them. But for game, you require a load suitable, and with enough pattern density and pellet energy to be deadly for the game being hunted, and the chokes to deliver it.

For the 28 ga., in my O/U, on the local "hunter's clays" course, I put in Trulock's Skeet 1 and Skeet 2 (a.k.a. light modified by some manufacturers), and use the selector switch to match the target sequence. (I am not a choke changer.)

For the local "championship course" of longer targets, I use the Trulock IC and Mod choke tubes in the 28.

And these are the same choke sequences I use in my larger gauges, as well.

 

Thanks for the response Bob. I was wondering how many people changed shot size to keep the pattern density up. I reload, so switching my 28's to smaller shot would probably be a very helpful tool. I'm surprised the change doesn't result in lost targets on the sporting clays courses. I guess I've always just accepted what people said about 7.5 being the smallest that will break clays past skeet distances.

Your point about application is an important one that I did not discuss in my original post. A buddy of mine generated some charts last year to help us decide on payload & choke required for quail and pheasant. At typical game load speeds, 8's have the power to kill quail at any practical range (40 and under), but to use all of that range with adequate shot density the chart says you need a full choke with 3/4oz of #8's. Predictably, MOD= 35 yds, IC = 30 yds., CYL = 25 yds. If you use 7.5 shot, you can take everything above and subtract 5 yards, roughly equating one choke. So all of this is starting to agree and make sense.

I'm still interested in hearing about other's experience, but it does seem like with the change in shot size, that you don't have to go up a choke constriction as I was originally concluding. I'm not sure about using 8.5's, but maybe 8's. I plan on patterning, but right now I only have a modified choke (gun was used). So I was hoping with everyone's advice here I would get the proper chokes the first time.

Quick update: I got an email from Trulock confirming their chokes use the same method as Carlson, each choke matching the % of shot across the gauges.

 

For skeet, I normally shoot Cyl/Sk in my 12, Sk/Sk in 20 and 28, and IC/IC in 410. (Choke doesn't matter much in 410, but I personally find IC gives me more substantive breaks on the skeet field than Sk's do. If I shot 410 skeet competitively, I would probably get a pair of I-Sk or tight-Sk chokes.) For sub-gauge sporting clays and FITASC, the sub targets are usually set a little closer and softer than 12 targets, even at bigger events. So I normally open up about ½ step over my normal 12 on chokes for sub, so that means LM/LM or IC/LM for all 3 subs. However, I definitely carry an M and IM for each for the occasional sub "separator" station you run into...

 

Hello: I shot two of my 28 gauge guns today. I also have a set of Briley Ultra Lite tubes for another gun. So for 28 gauge I reload using #8 1/2 shot, 20/28 powder and AA hulls. For skeet I am using 0.003-0.005" chokes. For sporting I am using 0.015-0.030" chokes depending on the course. For 410 0.007-0.010 for skeet, 0.0010-0.014 for sporting. 410 I am using 300MP, #8 1/2 shot and AA hulls. You are going to love the 28 gauge! Thanks, Eric

 

Well, go to a range and look at the "unbroken" clays. Very often, they will have one, two, three, and sometimes even more holes in them, but they didn't break and they were scored a miss.

For a clay target, a larger pellet with more energy can easily pass through a clay, using most of its energy on a tree or rock beyond. The smaller pellets will put a higher percentage of their lesser energy into the target.

The 8 1/2s work fine in a 28 ga. I also have a buddy who reloads 7/8 oz. of 8 1/2s in his 12 ga. and swears by 'em. And it's amazing to see some of the long-distance breaks we get!

And remember, a miss is a miss no matter how much shot of any size you throw at the target!

 

I don't pay much attention to what is marked on a choke tube except to help me identify which tube it is. If I want to know something about the pattern it will throw with a certain shot size, I'll load it up with that shot size and pattern it on paper to see what it will do.

Then, when it comes time for me to select a choke tube for a certain shot, I simply select the choke tube that will give me the pattern that I think is best for that presentation.

I realize that this is too complicated for SOME shooters, but I have no problem selecting the choke/pattern that I think is best and then concentrating on the shot that I'm about to take.

As for shot size, if an 8.5 pellet will break a target out of a 28 gauge, then the same pellet at the same (or very similar) velocity will break a target out of a 12 gauge. The target doesn't know what gauge the pellet came from.

 

When I have looked at the choke offerings from manufacturers they name them in .005 increments.
.005 being skeet, .010 IC etc. Constriction and pattern are somewhat related, but I have seen some IC's pretty loose because what some call IC may have been around .007 or so. I saw comment on Tru lock once where he stated that pattern test are needed to determine what one is shooting "but if you want to trust the designation, that's OK too" With the advent of screw in chokes we tend to collect quite a few tubes as if the target will pause in the air until we can change chokes. A hand loader can often gain or lose about one constriction designation, as in making a light mod out of a IC or a skeet out of an IC. Some have gotten light full patterns out of mod and Improved modified will often give full patterns.
Smaller gauges also tend to require less constriction to get the same %. I have seen charts to support this. The 410 is standardized at 25 yards but really uses about a IC constriction which would give about the same % with larger gauges. Possibly the 410 bore is so small that it tends to get over choked at more constriction. You have constrictions designated at different chokes and also patterns designated. Take your pick. When I patterned the 28 it did tend to "follow the choke"

DP

 

 

I use the 308 pellet count of 3/4 ounce of #8 as my gauge of how things should pattern with different shot sizes and gauges. How ever I quit using #8.5 except for the 410 (1/2 oz). So it is #8 for my 20, 28, and 410 (11/16 oz). #7.5 works better for freezing temps on bio-birds. I use a one ounce load of #7 for December grouse with its 298 pellet count.

I just bought a IMPSKT which is .002" less restriction than IC for my 28 & 410 for clay's. Just shot an 85 with my 28 gauge at a shoot where the 96 was the highest score shot with 12 gauge.

 

Why does Briley and Browning have different restrictions between chokes for the 20 ga s Trulock and Carlson? Trulock and Carlson go by the .005 between chokes where Briley and Browning are .003 or .004

 

brabuser,
I pattern my guns, with the different screw in chokes and i also use a lot of SpredR shells when doing so.
Its the only way you can see what kind of bird killing patterns you actually have with your different chokes at different yardages.

all the best,

Pine Creek/Dave
L.C. Smith Man

 

Not a 12ga to 28ga comparison here... But this is a previous post of mine that may be helpful.

Will a 20-gauge 7/8-ounce load pattern "better" than a 20-gauge 1-ounce load?

Will a 20-gauge 1-ounce load pattern “better” than a 12-gauge 1-ounce load?

Let’s see what the pattern board can tell us about these two questions using my guns/chokes and Winchester AA target loads.

First, let’s see how the 20-gauge 7/8-ounce load compares to the 1-ounce load.

Patterning results from a 20-gauge Browning Citori with 28" Invector-plus barrels and Briley flush chokes (patterns average of five, 30" post-shot inscribed circle, yardage taped muzzle to target, and in-shell pellet count average of five).

20 GA 2 ¾” WINCHESTER AA TARGET LOAD
7/8 oz #8 lead (356 pellets) @ 1200 fps
20 YARDS -- CYL / pattern 301 (85%)

30 YARDS -- CYL / pattern 182 (51%)
30 YARDS -- SK / pattern 230 (65%)
30 YARDS -- IC / pattern 257 (72%)
30 YARDS -- M / pattern 318 (89%)

40 YARDS -- IM / pattern 225 (63%)
40 YARDS -- LF / pattern 246 (69%)
40 YARDS -- F / pattern 240 (67%)
40 YARDS -- XF / pattern 259 (73%)

20 GA 2 ¾” WINCHESTER AA HEAVY TARGET LOAD
1 oz #8 lead (410 pellets) @ 1165 fps
20 YARDS -- CYL / pattern 334 (81%)

30 YARDS -- CYL / pattern 216 (53%)
30 YARDS -- SK / pattern 237 (58%)
30 YARDS -- IC / pattern 276 (67%)
30 YARDS -- M / pattern 341 (83%)

40 YARDS -- IM / pattern 270 (66%)
40 YARDS -- LF / pattern 277 (68%)
40 YARDS -- F / pattern 272 (66%)
40 YARDS -- XF / pattern 291 (71%)

When comparing results from the same choke, the 7/8-ounce load usually (but not always) registered higher pattern percentages than the 1-ounce load and the 1-ounce load always put more pellets in the pattern than the 7/8-ounce load.

Now, let’s see how the 20-gauge 1-ounce load stands up against the 12-gauge 1-ounce load.

Patterning results from a 12-gauge Browning Citori with 28" Invector-plus barrels and Briley flush chokes (patterns average of five, 30" post-shot scribed circle, yardage taped muzzle to target, and in-shell pellet count average of five).

12 GA 2 ¾” WINCHESTER AA EXTRA-LITE TARGET LOAD
1 oz #8 lead (393 pellets) @ 1180 fps
30 YARDS -- CYL / pattern 218 (55%)
30 YARDS -- SK / pattern 256 (65%)
30 YARDS -- IC / pattern 305 (78%)

40 YARDS -- LM / pattern 251 (64%)
40 YARDS -- M / pattern 292 (74%)
40 YARDS -- IM / pattern 295 (75%)

Obviously, the only way to really know how a load/choke combo will perform in your gun/choke is to pattern it! That said, there are some general tendencies concerning this 20- vs 12-gauge question that can be made. A 12 gauge is usually more efficient than a 20 gauge; it usually takes a degree or two of choke tighter in the 20 gauge to reach similar 12-gauge pattern density; and when you get beyond ~40 yards, the 12 gauge will almost always be capable of putting more pellets in the pattern than the 20 gauge.

Is one more “effective” than the other?

I'll let you be the judge of that!

 

M/M for everything in all sub-gauges. I have shot numerous 25’s in skeet especially in 28ga and .410 and I am not a skeet shooter. I have also achieved Masterclass in subs and I shoot M/M exclusively. M/M just seems to work.

 

For sporting I shoot mod/mod for 20 & 28, full/full for 410. So far so good. I was shooting mod for 410 and lagging behind my typical scores. A buddy suggested going to full. Now it’s typically my best event.

 

For equal bore cross sectional area of constriction percentages I calculate:

12 Gauge 0.040" Constriction = 20 Gauge 0.0337" Constriction
12 Gauge 0.035" Constriction = 20 Gauge 0.0295" Constriction
12 Gauge 0.030" Constriction = 20 Gauge 0.0253" Constriction
12 Gauge 0.025" Constriction = 20 Gauge 0.0211" Constriction
12 Gauge 0.020" Constriction = 20 Gauge 0.0168" Constriction
12 Gauge 0.015" Constriction = 20 Gauge 0.0126" Constriction
12 Gauge 0.010" Constriction = 20 Gauge 0.0084" Constriction
12 Gauge 0.005" Constriction = 20 Gauge 0.0042" Constriction

12 Gauge 0.040" Constriction = 28 Gauge 0.0302" Constriction
12 Gauge 0.035" Constriction = 28 Gauge 0.0264" Constriction
12 Gauge 0.030" Constriction = 28 Gauge 0.0226" Constriction
12 Gauge 0.025" Constriction = 28 Gauge 0.0189" Constriction
12 Gauge 0.020" Constriction = 28 Gauge 0.0151" Constriction
12 Gauge 0.015" Constriction = 28 Gauge 0.0113" Constriction
12 Gauge 0.010" Constriction = 28 Gauge 0.0075" Constriction
12 Gauge 0.005" Constriction = 28 Gauge 0.0038" Constriction

12 Gauge 0.040" Constriction = 410 Bore 0.0225" Constriction
12 Gauge 0.035" Constriction = 410 Bore 0.0196" Constriction
12 Gauge 0.030" Constriction = 410 Bore 0.0169" Constriction
12 Gauge 0.025" Constriction = 410 Bore 0.0141" Constriction
12 Gauge 0.020" Constriction = 410 Bore 0.0113" Constriction
12 Gauge 0.015" Constriction = 410 Bore 0.0084" Constriction
12 Gauge 0.010" Constriction = 410 Bore 0.0056" Constriction
12 Gauge 0.005" Constriction = 410 Bore 0.0028" Constriction

 

In all small gauges I use M/M, or Mod/IMod. Open chokes are for hopers not shooters.

 

Dang, I've been defined.

 

first I only shoot Skeet
i don’t shoot 12ga
the sub gauge chokes I use———wait for it

Skeet

 

I'm relatively new to subgages and I need to get tubes for my shotgun. While trying to decide on which constrictions to buy I realized there are differences from 12 gauge and it started a interesting research project. Mostly, I was wondering about how choke tube manufacturers decide a choke tube is labeled for subgages, and if it's different than 12 gauge . . .

You pays your money and you takes your chances. Briley supplies one set of chokes with their subguage tubes. You flip a coin and decide. There's no law that says you have to stick with your initial choice. You can buy additional chokes when you buy the tubes. Or, you can change your mind. If you're dissatisfied after trying the chokes that came with the tubes you can get some different ones.

 

Roughly, for the Nominal 12 Gauge:
-----------------------------------------------
12 Gauge 0.040" Constriction = Turkey Choke
12 Gauge 0.035" Constriction = Extra Full Choke
12 Gauge 0.030" Constriction = Full Choke
12 Gauge 0.025" Constriction = Improved Modified Choke
12 Gauge 0.020" Constriction = Modified Choke
12 Gauge 0.015" Constriction = Light Modified Choke
12 Gauge 0.010" Constriction = Improved Cylinder Choke
12 Gauge 0.005" Constriction = Skeet Choke
12 Gauge 0.000" Constriction = Cylinder Choke

Apply these common choke names accordingly to other gauges as seen in my post #16 above.

 

I shoot a lot of 28 ga on FITASC and 5-stand. I use two different Krieghoffs … both with Briley chokes. For me, my guns and my fields, M/M is what I normally use. If the course is set with a mix of soft and longer targets, I may switch to M/IC.

 

The real problem is unclear nomenclature. What we call them means nothing. What they show on a pattern board says everything. In small gauge SC's there are some long(ish) targets. Meaning up to 50 yds.

 

I couldn't agree more, but I will add that if one knows the degree of constriction that any given choke will factually deliver within their particular guns barrel, the odds of achieving success at the pattern board are increased.

 

There are several problems w/ guessing. And a big plus in having a tighter pattern. The target may be farther than you thought.

 

I use what I'd use with the 12 -- it simplifies my choices. That said, most sub FITASC's even at majors are set on the softer side, and here LM/M is my goto; if really soft, IC/LM. This years US Open however, had a stupid long full-spring, steep quartering away chandelle batteau, that was at 55 or 60 yards before you could get on it on Par 2 of the 28 ga course -- that one needed M/IM and I still struggled...

 

I purchased a 28 gauge K20 Parcours with 32" fixed choke barrels in May of 2022. I called Kreighoff with the barrel number and they told me the chokes were standard at .020 and .030. When I do my job the targets break.

 

The tightest pattern does not at all define a superior choke. The choke that delivers a specific load at a uniformly distributed percentage of pellets (with appropriate center weighting) commensurate with the desired pattern percentage is the superior choke. For the case of a 30" circle at 40 yards that 'superior' choke may be the one which nominally delivers as follows (for lead shot):

~80% = Turkey Choke
~75% = Extra Full
~70% = Full
~65% = Improved Modified
~60% = Modified
~55% = Light Modified (or Skeet 2)
~50% = Improved Cylinder
~45% = Skeet 1
~40% = Cylinder

The names printed upon chokes are largely irrelevant. The relationship between the chokes measured constriction and the bores measured inner diameter is largely relevant. It is the bores cross sectional area of choke constriction (as a percentage) which largely (or perhaps better, nominally) defines the 'expectation' of pattern percentage for lead shot.

For balanced constriction percentages across the Gauge/Bore spectrum I compute that:

12 Gauge: 0.040" Constriction ~= Turkey Choke ~= 80% into a 30" circle @ 40 Yards
12 Gauge: 0.035" Constriction ~= Extra Full Choke ~= 75% into a 30" circle @ 40 Yards
12 Gauge: 0.030" Constriction ~= Full Choke ~= 70% into a 30" circle @ 40 Yards
12 Gauge: 0.025" Constriction ~= Improved Modified Choke ~= 65% into a 30" circle @ 40 Yards
12 Gauge: 0.020" Constriction ~= Modified Choke ~= 60% into a 30" circle @ 40 Yards
12 Gauge: 0.015" Constriction ~= Light Modified Choke ~= 55% into a 30" circle @ 40 Yds
12 Gauge: 0.010" Constriction ~= Improved Cylinder Choke ~= 50% into a 30" circle @ 40 Yards
12 Gauge: 0.005" Constriction ~= Skeet 1 Choke ~= 45% into a 30" circle @ 40 Yards

20 Gauge: 0.0337" Constriction ~= Turkey Choke ~= 80% into a 30" circle @ 40 Yards
20 Gauge: 0.0295" Constriction ~= Extra Full Choke ~= 75% into a 30" circle @ 40 Yards
20 Gauge: 0.0253" Constriction ~= Full Choke ~= 70% into a 30" circle @ 40 Yards
20 Gauge: 0.0211" Constriction ~= Improved Modified Choke ~= 65% into a 30" circle @ 40 Yds
20 Gauge: 0.0168" Constriction ~= Modified Choke ~= 60% into a 30" circle @ 40 Yards
20 Gauge: 0.0126" Constriction ~= Light Modified Choke ~= 55% into a 30" circle @ 40 Yards
20 Gauge: 0.0084" Constriction ~= Improved Cylinder Choke ~= 50% into a 30" circle @ 40 Yds
20 Gauge: 0.0042" Constriction ~= Skeet 1 Choke ~= 45% into a 30" circle @ 40 Yards

28 Gauge: 0.0302" Constriction ~= Turkey Choke ~= 80% into a 30" circle @ 40 Yards
28 Gauge: 0.0264" Constriction ~= Extra Full Choke ~= 75% into a 30" circle @ 40 Yards
28 Gauge: 0.0226" Constriction ~= Full Choke ~= 70% into a 30" circle @ 40 Yards
28 Gauge: 0.0189" Constriction ~= Improved Modified Choke ~= 65% into a 30" circle @ 40 Yds
28 Gauge: 0.0151" Constriction ~= Modified Choke ~= 60% into a 30" circle @ 40 Yards
28 Gauge: 0.0113" Constriction ~= Light Modified Choke ~= 55% into a 30" circle @ 40 Yards
28 Gauge: 0.0075" Constriction ~= Improved Cylinder Choke ~= 50% into a 30" circle @ 40 Yds
28 Gauge: 0.0038" Constriction ~= Skeet 1 Choke ~= 45% into a 30" circle @ 40 Yards

410 Bore: 0.0225" Constriction ~= Turkey Choke ~= 80% into a 30" circle @ 40 Yards
410 Bore: 0.0196" Constriction ~= Extra Full Choke ~= 75% into a 30" circle @ 40 Yards
410 Bore: 0.0169" Constriction ~= Full Choke ~= 70% into a 30" circle @ 40 Yards
410 Bore: 0.0141" Constriction ~= Improved Modified Choke ~= 65% into a 30" circle @ 40 Yards
410 Bore: 0.0113" Constriction ~= Modified Choke ~= 60% into a 30" circle @ 40 Yards
410 Bore: 0.0084" Constriction ~= Light Modified Choke ~= 55% into a 30" circle @ 40 Yards
410 Bore: 0.0056" Constriction ~= Improved Cylinder Choke ~= 50% into a 30" circle @ 40 Yds
410 Bore: 0.0028" Constriction ~= Skeet 1 Choke ~= 45% into a 30" circle @ 40 Yards