Shotgun Choke Tubes

I’m not going to pretend that I know what I am talking about on this, So I added some info from the web site listed attached.

ShotgunLife.com - Choke Tubes

Shotgun Chokes

Count yourself lucky that some genius invented the screw-in shotgun choke. Otherwise, you’d probably need five shotguns.

Adjustable shotgun chokes give you the ability to change the pattern of your shot by tailoring the constriction. The baseline constriction is cylinder -- or the inner diameter of your barrel. From there, the designations grow tighter.

Choke Bore Sizes and Constrictions

	CYL	LTSK	SK	IMK	IC	LM	M	IM	LF	F	XF	D
12 Bore	.000	N/A	.005	N/A	.010	.015	.020	.025	.030	.035	.040	.005 and Rifled!
20 Bore	.000	.003	.005	.007	.009	.012	.015	.018	.021	.024	.027	.005 and Rifled!
28 Bore	.000	.003	.005	.007	.009	.012	.015	.018	.021	.024	.027	N/A
.410 Bore	.000	.003	.005	.007	.008	.010	.012	.014	.016	.018	.020	N/A

(Courtesy of Briley Mfg.)

*Abbreviations:
CYL = Cylinder
LTSK = Light Skeet
SK = Skeet
IMK = Improved Skeet
IC = Improved Cylinder
LM = Light Modified
M = Modified
IM = Improved Modified
LF = Light Full
F = Full
XF = Extra Full
D = Diffusion
N/A = Not Applicable

Looking at the chart, you’ll see that SK (skeet) imposes a .005% constriction compared to cylinder. Full gives you a .035% constriction. Yes, that’s a 600% difference.

Percentage of Constriction Based on Distance
Choke	20 Yards	30 Yards	40 Yards
Cylinder	80%	60%	40%
Skeet	92%	72%	50%
Improved Cylinder	100%	77%	55%
Modified	100%	83%	60%
Improved Modified	100%	91%	65%
Full	100%	100%	70%

In this chart, you’ll notice that as the choke grows tighter (from cylinder to full) the density of the pattern increases based on distance.

That’s because tight chokes distribute the shot in a tight, dense pattern best for long shots. Open chokes give you a wider, diffused pattern intended for close shots.

If this sounds counter-intuitive, here’s the way it works.

You may be thinking that you want the wider pattern for longer shots because the target is further away. The longer the distance, logic dictates the wider the pattern giving you a better chance to hit the target.

But what you’re not taking into account are the laws of physics.

Smaller shot (which tends to be used for close shots of 16-20 yards) lacks the energy (momentum) to give you accuracy at longer range. The shot spreads willy-nilly and you lose accuracy.

So if you’re going for a long shot, you want to use a bigger pellet in a tighter shot string for an arrow-head effect. Hence, a tighter choke.

For close-range shots, as in skeet, physics dictates that the more pellets you shoot the greater the odds for hitting the target before the smaller (lighter) pellets lose their momentum. So you want to go for a wider choke that lets the smaller, lighter pellets actually swarm around the target while they’re still effective.

Basically, there are three types of chokes.

The fixed choke is already machined into the barrel of the shotgun. You’ll see guns that are designated with skeet chokes, or full and improved cylinder chokes for wingshooting. The type of chokes depends on its specialized use, and will often be accompanied by stock and sight complements.

When you buy a new shotgun, it will include a few screw-in chokes most appropriate for its design. You usually can purchase after-market chokes to fill out your inventory.

Screw in chokes come in two varieties: extended and flush mounted.

Extended chokes protrude above the muzzle and are generally clearly marked; they are designed to be screwed in by hand.

Flush-mounted chokes are screwed entirely into the barrel so that in the end the choke is flush with the muzzle. Newer flush-mounted chokes tend to also be clearly identified. But less expensive or older flush-mounted chokes rely on a notch system to identify their constriction.

Choke	Notches
Cylinder	/////
Skeet	/////
Improved Cylinder	////
Modified	///
Improved Modified	//
Full	/

Then there’s the adjustable choke. This is a single choke with multiple settings. Turn the selector to set the most appropriate constriction.

Once you have the choke installed, it’s best to pattern it on paper.

You’ll need a pattern target and something disposable to mount it on.

Typically, you’d want to be about 40 yards from your “pattern board.” Draw a 30-inch circle around the center of the pattern and then count the pellets as a means to determine the accuracy of your choke. A full choke should put 70% of its pellets in a 30" circle at 40 yards. A modified choke should put 60% of its pellets in the circle. And an improved cylinder should give you 50%.

Perhaps the biggest risk with chokes is that they become a crutch.

For example, if you consistently missed the #3 station on skeet with a skeet choke, moving to a wider cylinder choke probably won’t help. After all, if you’re on the target, you’re on it. The same can be said of most other clays sports.

Missing shots is generally not a function of your choke selection. It’s a function of your skill, technique and body mechanics.

The worst mistake you can make with a choke is using it as an excuse for missed shots.

If you have a problem station, and you’re using the recommended choke, the best thing you can do is practice, practice, practice.

My thoughts:

I'm thinking in the same direction of the last paragraph above.  Practice and time in the field is going to improve your ability’s.  If you worry too much about all of this it changes the game and you might as well take up golf.  Use what works for you!!! and keep in mind that some experimenting can make big improvements to your understanding of why you missed.  Keep in mind also, that you have to take into account the type of powder, wad, and shot that you are using.  However, you don't have time to change chokes and shells as the birds are flying away.  Some of the best practice you can get is at a Sports Clay range.  Take a month of weekends and try it out, it’s a lot of fun and your wife will enjoy making a date out of it.  Or( my preference) you can take a trip to "Lake in the Dunes" and do it all. 

http://www.lakeinthedunes.com/

http://thegrindstonelakes.com/

Some more charts:

Chuckar's vs Hun's

“What is the difference between a Chuckar and a Hungarian partridge?” My initial reply, “Ask a biologist,”

My thoughts:
Chuckars or Huns it doesn't matter they are both fun and hard to hunt.  Huns don't seem to talk as much and stay to lower grassier country when hunting in areas with Chuckars, in my perception.  They taste similar, and still raise your feathers if they jump next to you.  You will probably shoot before you know you are aiming at a different type of bird.  I like Chuckars better, with their bandit / outlaw looks and their extreme behavior, also added personality, they are the 30" Moss Back Mule Deer of bird hunting, challenging and rewarding.

Hunting tips:
Try to find places where you can see where the birds land after jumping them.  Flat land is best if you can find them in it.  Areas that have short distances between ridges are also good, otherwise you will limit your chances of 2nd and 3rd jumps.  Best hunting comes after the first jump, unless you have a slight wind, and a good dog.  Use of ATV's, trucks, and boats, is only for youth(9-14), thoughts with actual disabilities( out of shape doesn't count) and Seniors(60 and up), unlawful and un-sportsman like.  Hunt where you know the birds are, not where you think they might be.  Take into consideration hunting pressure, weather, time of the year, Chuckar habits change during the course of the year.  Always take a partner, and wear boots with good traction and ankle support.  Keep plenty of water on you and stored away for rehydration after the hunt.  Clothing is of Course dependent on weather, but use several layers because you will be shedding them and replacing them during the course of the day.

Shot Size and Pattern:
Shot size = 4 to 7 1/2:  However use what it takes and what works for you.  12g 3.5in mag steel has been used.  I prefer 6 = 1st shot, 5 = 2nd and 3rd shot, but that depends on the area, and how tight the birds are holding.  Pattern = Modified: However use again what it takes and what works for you.  Full chokes to Skeet chokes have been used.  I prefer IM - II notches because I am a bit slower draw then most upland hunters.  Seriously,  If you don't want to guess - "Pattern your gun" - Or shoot a decoy or two, you might feel silly, but you will know exactly your range and accuracy.  I will add a updated data sheet on Choke Tubes asap.

Chuckar Partridge

Description:
The Chuckar is a rotund 32–35 cm (13–14 in) long partridge, with a light brown back, grey breast, and buff belly. The shades vary across the various populations. The face is white with a black gorget. It has rufous-streaked flanks, red legs and coral red bill. The tail has 14 feathers, the third primary is the longest while the first is level with the fifth and sixth primaries

Heritage:
(Alectoris choker) is a Eurasian upland game bird in the pheasant family Phasianidae. The species has been introduced into many other places and feral populations have established themselves in parts of North America and New Zealand.

Habitat:
Its native range is rocky open hillsides with grass or scattered shrub or cultivation. It is mainly found at an altitude of 2000ft to 13000ft(600 to 4000 m). They are not found in areas of high humidity or rainfall.

Distribution:
US = Rocky mountains, high desert areas near water, and canyon lands.

Behavior:
In the non-breeding season, Chuckar Partridge are found in small coveys of 5 or more (up to 75) birds. In summer, Chuckars form pairs to breed. During this time, the cocks are very pugnacious calling and fighting.  During winter they descend into the valleys and feed in fields. The call frequently during the day especially in the mornings and evenings. The call is loud and includes loud repeated "Chuck" notes and sometimes dieting "Chuckar" notes. When disturbed, it prefers to run rather than fly, but if necessary it flies a short distance often down a slope on rounded wings, calling immediately after alighting. Study's found that they forage in an area of about 1.5 square miles (2.6 km2). and travel up to 3 miles (4.8 km) to obtain water during the dry season. They lay about 7 to 14 eggs per hatch. The eggs hatch in about 23–25 days.  Chuckar will take a wide variety of seeds and some insects as food.  Chuckar roost on rocky slopes or under shrubs. In winter, birds some times select protected niches or caves. A group may roost in a tight circle with their heads pointed outwards to conserve heat and keep a look out for predators.

Determine Gender:
Sexes are similar, the female slightly smaller in size and lacking the spur.

Grey Partridge (Hun)

Description:
The Grey Partridge is a rotund bird, 28–32 cm long, brown-backed, with grey flanks and chest. The belly is white, usually marked with a large chestnut-brown horse-shoe mark in males, and also in many females.

Heritage:
The Grey Partridge, Perdix perdix, also known as the English Partridge, Hungarian Partridge, or Hun, is a game bird in the pheasant family Phasianidae of the order Galliformes, gallinaceous birds. The species has been successfully introduced to many parts of the world for shooting, including vast areas of North America, where it is most commonly known as Hungarian partridge, or just "Hun"

Habitat:
They nest is usually in the margin of a cereal field, most commonly winter wheat.  They are normally found in grass land areas even at high altitudes, but prefer lowland outcroppings, drainages, and bluffs.

Distribution:
These birds are found through out the plains states, South Dakota, Wisconsin, Montana, also Idaho and Oregon.

Behavior:
Hens lay up to twenty eggs in a ground nest. The song is a harsh kieerr-ik, and when disturbed, like most of the game birds, it flies a short distance on rounded wings, often calling rick rick rick as it rises. They are a seed-eating species, but the young in particular take insects as an essential protein supply. 

Determine Gender:
The only major and constant difference between the sexes is the so-called cross of Lorraine on the tertiary coverts of females – these being marked with two transverse bars, as opposed to the one in males. These are present after around 16 weeks of age when the birds have molted into adult plumage.

Maybe this helps?

Your thoughts?

Referenced from:

Wikipedia, the free encyclopedia