How can I identify a shotgun choke at home?

[Kev18]

I heard people talking about using a nickel to check but it doesnt work. Im canadian and out nickels are a few hundredths bigger. I was wondering if there was any other solution other then buying a gauge. Something easy that I could do at home. I have a 10 gauge and 12 gauge. Id just like to know in general.
12:

10:

[turtlezx]

calipers mic the bore

[Der Gebirgsjager]

Buying a gauge would be the easiest way. www.brownells.com Item # 774-100-104WB Royal Quick Check Choke Gauge. Unfortunately, presently out of stock, you can back order. Only $9.99. You know you need one in your tool box. Sure to use it again "down the road."

[BK7saum]

If you have a set of dial or vernier calipers, just measure bore ID. There is a list if choke constrictions on the web. It'll get you pretty close.

They are listed at 0.005" intervals from a nominal bore diameter of 0.730" for a 12 gauge.

[BK7saum]

Cylinder is 0.730 or 0.000 construction.
Skeet 1 is 0.725 or 0.005 consriction, etc

Cylinder .000 40 at 40 yds- 70 at 25 yds
Skeet 1 .005 45 at 40 yds- 75 at 25 yds
Imp Cyl .010 50 at 40 yds
Skeet 2 (lite mod) .015 55 at 40 yds
Modified .020 60 at 40 yds
Imp Mod .025 65 at 40 yds
Full .030 70 at 40 yds
Extra Full .040 73 at 40 yds
Turkey .045 Plus 75 PLUS at 40 yds

[MusicMan]

And if you bore is more or less than 0.730 everything is out the window!

[W.R.Buchanan]

BK7 has the right numbers in post #5. Just use your calipers to measure the ID of the barrel at the muzzle and look at the chart.

That should be everything you need to figure out the chokes on those guns.

Randy

[Winger Ed.]

Usually barrels are marked, maybe in a code with 1,2, or 3 star looking marks.
Research the maker, and it might tell ya how to read it by barrel markings.

[MT Chambers]

You don't check with a nickel, you use a dime and compare with a known choke from another std. 12 gauge. This is not valid for use on competition shotguns that are over bored and are choked accordingly.

[Petander]

You don't check with a nickel, you use a dime and compare with a known choke from another std. 12 gauge. This is not valid for use on competition shotguns that are over bored and are choked accordingly.

Yes. The choke "degree" is related to the barrel diameter.

Whatever they measure or read, I shoot mine @ 35 meters (40 yds) and see how much % of shot I get in 75 cm. (30") circle.

[Petrol & Powder]

A U.S. Dime is 0.705" in diameter.

So typically..........a 12 gauge modified choke will allow a dime to be inserted into the muzzle and a Full choke will not take a dime.

However, Petander has the right idea.

[Kev18]

Other then a calipers, there is no tool I could make? I dont have a lathe.

[Petrol & Powder]

A simple "step" gauge made from a piece of flat stock that has a series of "steps" cut and filed to known dimensions would be easy to make but somewhat time consuming to create. It will not give you a precise measurement but it will give you a "go / no-go" determination for each step.
Frankly, I would just buy one.


https://www.brownells.com/gunsmith-t...prod10984.aspx

or

https://www.midwayusa.com/product/81...tainless-steel

[JBinMN]

If ya want to go "cheap/frugal" & not buy a gauge & you don't trust measuring the inside with a calipers, you can convert to an outside measurement that will "get ya close" but taking a funnel shaped piece of sturdy paper/light cardboard ( cereal box type), taped into a slender cone shape, that is smaller them out to larger than bore, and stick the little end into the muzzle, take a sharp pencil/finely tipped pen & mark the point where the funnel cone meets the muzzle, remove it & then measure the outside diameter on the cone where the marks are. ( You can even put some shot into the inside of the funnel/cone to help hold the sides out for when ya press to mark the sides if ya wanted to do that.)

You could do the same with a small plastic funnel & put a couple strips of tape on opposite sides of the funnel & then a sharp pen or marker, do the same as above with the paper one to get a relatively close measurement.

You could even just put the calipers on the funnel/cone while it is on the muzzle & measure that way without marking if ya hold the funnel/cone tight against the muzzle.

Lastly, and similarly, you can just roll up a piece of sturdy paper and insert it partway into the bbl, then let it relax out to the inside diameter, tape the seam together , then remove the paper & measure the OD of it while taped into a roll, being careful not to compress the roll into an oval, or put something inside it to hold its round shape to measure

That should get ya mighty close, if you are particular on doing it.

That is about the simplest way I can think of to convert from an inside measurement to outside measurement without spending any , or little $4.

G'Luck whatever ya do!

[Markopolo]

JB has a great idea... looky looky at the post above... and if you can’t get it measured, you can send me that Winchester type lever shotgun and not have to worry about it...

[EDG]

Choke determination requires 2 measurements.
First you need the bore diameter then the choked dimension.
Subtract the choked dimension from the bore diameter.
The difference is the constriction.
Many imported shotguns like the Japanese Howa have .725 bores.
American 12 ga guns are usually .729 unless backbored oversize.
The newer back bored guns have larger bores and use different choke tubes.
I have a Howa made Smith & Wesson 3000 pump with a .725 bore.
Win chokes fit it but they give a different amount of constriction on the Howa. An IC Win choke has no constriction when on the Howa.

I have a set of telescoping gauges and use them with a micrometer to measure barrels and chokes. But measuring is often just an exercise. The real measure is shooting the gun at a sheet of paper with the actual ammo. Not some ammo but the exact shells you intend to hunt or compete with.
Cheap promotional shells and reloads using cheap shot will give more open patterns.
Premium heavy trap loads will pattern much better. So does the harder magnum shot.
Wads can also change the patterns.

[rking22]

The purpose of choke is to control the pattern distribution and is measured in % of the pellets in a 30 inch circle at 40 yards. Measuring the bore and choke to arrive at a "constriction" is a frequently used expedient, also how they are sold. Not all .030 constrictions will throw the 70% pattern, heck if it's a tula type choke all the deminsions are in question. Also no trlling what some prior owner may have altered.Post 5 has the percentages for each choke. All you need is a shell with a known number of pellets, shoot it at a paper target at 40 yards. Then draw a circle arround the most pellets ,30 inch dia. Count them and devide by what was in the shell. That is the real choke of that gun. Over simplified but better than iffy muzzle measurments.
I just shoot mine at a pattern board and look and go, yeah "tight" ,or about a Mod, or "good bird gun". Thats really all you care, right? But I have been playing with shotguns for 40 years.

[Petrol & Powder]

The purpose of choke is to control the pattern distribution and is measured in % of the pellets in a 30 inch circle at 40 yards. Measuring the bore and choke to arrive at a "constriction" is a frequently used expedient, also how they are sold. Not all .030 constrictions will throw the 70% pattern, heck if it's a tula type choke all the deminsions are in question. Also no trlling what some prior owner may have altered.Post 5 has the percentages for each choke. All you need is a shell with a known number of pellets, shoot it at a paper target at 40 yards. Then draw a circle arround the most pellets ,30 inch dia. Count them and devide by what was in the shell. That is the real choke of that gun. Over simplified but better than iffy muzzle measurments.
I just shoot mine at a pattern board and look and go, yeah "tight" ,or about a Mod, or "good bird gun". Thats really all you care, right? But I have been playing with shotguns for 40 years.

/\ Several posters have made these points but I think this hits it on the head. /\

As for the measurements being an expedient, that's very true but it's an expedient that works fairly well. As Petander stated in post #10 (and several others echoed) it's the results that really matter.

However getting back to the field expedient of using a coin and the OP's question, A U.S. Dime is .705" in diameter. The use of a dime to check the diameter at the muzzle doesn't tell you much BUT it does tell you a little. It tells you if the inner diameter at the muzzle is smaller than .705" or larger than .705". It doesn't tell you the diameter of the bore before the choke, nor does it tell you how much over or under the muzzle diameter is compared to the dime and it certainly doesn't tell you the actual performance on a pattern board - but it gives you more information than just looking at the muzzle !

[Kev18]

Anyone know the choke on an 1887 lever action shotgun. I just measured mine and the biggest number I got was .706. That would be a full choke from the charts I looked at right?

[Petrol & Powder]

Depends of the diameter of the bore BEFORE the choke.

However, assuming the bore diameter is .729" (typical for American 12 gauge but varies a bit) then a muzzle diameter of .706" would be consistent with full choke. BUT, as stated several times; results, not measurements, matter.