How does a choke work ?

[Mike_in_OC]

While shooting today my friend and I got into a debate on how a shotgun a choke works. He said the choke works like a funnel thus makes the pattern tighter. I always thought the choke was used to slow the wad down and not disturb the shot. I've heard both versions on the net. Any experts..... Thanks Mike

 

[mattw]

i think funnel

 

[mete]

Sorry , you're wrong Mike ! In fact today's plastic shot cup has 'fingers' that open up after it leaves the barrel and the cup slows very quickly.Though there are different choke designs they basically act as a funnel. Always pattern your loads.

 

[mod12]

think of it as a nozzle on a hose. the more you constrict it, the more concentrated the stream (pattern) becomes.

 

[Radamanthus]

I used to believe that it was the funnel theory, until a friend of mine, who knows nothing about guns, brought up the point that the shot is in the shot cup until it leaves the barrel. How is the shot being funneled into a tighter group if it is in the plastic cup that holds it as tight as possible?

 

[mod12]

it is the amount of constriction at the moment the cup leaves the bbl. that determines the distribution of shot within the pattern at 40 yds. the cup serves to protect and buffer the shot within the shell during its travel thru the bbl., separates and falls away a short distance from the muzzle.

 

[rockstar.esq]

The choke constricts the wad against the shot which causes the wad to stay with the shot for a bit longer. The effect is that the shot is held together for a little greater distance proportionate to the amount of constriction. Please note that this only works this way when you are using the shot intended by the choke design. A great example of this is using a buckshot load with a turkey choke. I've seen patterns shot using a turkey choke that were way wider than patterns shot using a plain ol' modified cylinder. My theory is that the larger buckshot "springs back" when it's choked too much. Can't prove it mind you.

 

['Card]

This has the potential to be a really interesting thread.

 

[Steve C]

Most chokes are a restriction like a nozzle on a garden hose and force the shot into a narrow stream which makes the pattern tighter. The common way to tell if a 12 ga is full or modified is to see if a dime will fit into the end of the barrel. It won't fit in a full choke but will in a modified.

There is however always a few examples that break the rules. Since the type of choke is defined by the % of shot that falls within a circle at a given distance there are some full choke guns that have no restriction at the muzzle and are instead choked in the earlier part of the barrel. I had a fried that shot a full choke Ljutic "bannana gun" barrel inside a barrel system and a dime would fall throught the barrel and out the breach. Don't know how that choke worked but it did.

 

[mod12]

i believe that modern shells play a more significant role in pattern today than in the days of paper shells and fiber wads. i have a mod. 12, 16 ga. with a 24" bbl. cut back from a mod. 28" bbl. that results in a true cyl. choke. it throws a pattern at 27 yds that is as nice as you'll find with low brass, 1 oz., #8 federal shells, my favorite grouse load. i think the cup results in less damage to the shot, resulting in fewer fliers and may in fact aid in limiting disruption to the payload as it exits the muzzle.

 

[Dave McCracken]

The two main Theories are already on this thread. Please feel free to take your pick.

I have no answer, and both theories make sense to me. So, I know what the results are and how to get them.

Until I achieve Nirvana and know everything about everything, I shall just use choke instead of musing on how it happens.

 

[TrapperReady]

i believe that modern shells play a more significant role in pattern today than in the days of paper shells and fiber wads. i have a mod. 12, 16 ga. with a 24" bbl. cut back from a mod. 28" bbl. that results in a true cyl. choke. it throws a pattern at 27 yds that is as nice as you'll find with low brass, 1 oz., #8 federal shells, my favorite grouse load.

Mod12 - My "grouse gun" is a 16ga Model 12 with a barrel right around 24", cut down from a full-choke barrel. Since it's a 1930 model with 2 9/16" chambers, I use 2 1/2" shells from Westley-Richards. The 7/8oz of #7 (not #7 1/2) shot patterns very evenly and has been good medicine for grouse and woodcock. Furthermore, I've yet to find any other gun which handles and shoots as well in heavy cover.

 

[GRP]

I think your both a little right
http://www.wadwizard.com/Works.htm

 

[mod12]

my mom and dad gave me mine for my birthday in 1952. they're grand old guns.

 

[sm]

Works as a scapegoat when you miss.

 

[TrapperReady]

Works as a scapegoat when you miss.

See also:

Brightness of the sun.
Rotation of the earth.
That guy coughed when I shot.
Those targets don't break right.
I think I'm coming down with something.
I was out too late last night.
There isn't enough antimony in this shot.
The trapper threw early.
The trapper threw late.
There's something wrong with the machine.
My glasses were smudged.

And my personal favorite....

@^&#ing rabbits!!!!

On a more serious note, I'm coming full-circle with respect to choke. I started out shooting pretty tight chokes, switched to more open ones, became a frequent choke changer... and now I'm back to tight chokes again. For me, I just tend to shoot with greater confidence when I'm smoking the closer targets. Also, the tighter chokes help me read the breaks and I seem to run stations more consistently when I'm using them.

 

[birddog]

I dunno. I think it's magic. I used improved/modified on my pheasant and woodcock guns. I use extra full on my turkey gun. Then there are the two turkeys I've killed at 40 yards with a load of 8's while woodcock hunting (two consecutive days, same area) with...an improved cylinder.

I still change my chokes to suit the situation, since I already own them, but am wondering if they aren't just something else to make the gun manufacturers a little more money...

"Oh sure, this one will tighten your groups right down to a dime at 75 yards...honest!"

 

[BluesBear]

The choke constricts the wad against the shot which causes the wad to stay with the shot for a bit longer. The effect is that the shot is held together for a little greater distance proportionate to the amount of constriction.

This "theory" doesn't address the fact that chokes worked just fine long before plastic shot cups.
The shot cup falls away at about the same distance from the muzzle regardless of the choke used.

The two main Theories are already on this thread. Please feel free to take your pick.

In reality the choke reacts with the shot both ways. The original purpose of the choke was to create a smaller diameter shot column. A side effect was the retarding of the wads.
When plastic shot cups came along patterns tightened up a little because there were less pellets deformed by barrel friction.
The choke retards these wads just like they did the old fashioned felt/card wads.
If you study high speed photography you can see the lengthened shot column spring back slighty after clearing the muzzle as the lower density shot cup is opened by air resistence as the shot outraces it.

 

[sm]

True Story

Back in the day, I bought a used Pump Gun for a beater, a loaner a...it was shoved into my hand as I was drinking the gun shops coffee, I still think they did that to keep me from snagging another cinammon twist...

The gun needed some attention, as the wood and and blue was great, the barrel needed tweaking to shoot consistent patterns.

First thing I had the guy do was remove the marking on the barrel stating what that fixed choked barrel "said it was".

Folks get a "choke marking" in their brain, on barrels the first thing anyone did was "read" the barrel marking.

I visited with the gunsmith guy , who grinning ear to ear, and especially after I said I wanted the marking gone. Everthing else from Mfg, city and state, to 2 3/4 " only shells to , all ususal markings - except no barrel designation.

He did the work, as I wanted, and we conferred on, gun tested along the way and I worked up loads.

Dove hunting , loan the gun with the loads for doves it shot best and folks felled doves, I mean they felled doves and wanted to buy that gun.

"Not for sale"
"What barrel is this, what is it 'choked' ?"
What do you want it to be ? " I would ask.
"IC"
"Then IC it is"

Repeat with different shooters and that gun was anything from Open Bore to Extra Full. Whatever they wanted it to be , I replied "it was".

I did the same thing on Ducks in flooded timber to Geese in fields to rabbit hunting to squirrel hunting to shooting slugs at deer to busting 25/25 on a skeet field to...

NO screw in chokes remember, no barrel marking either. I would loan the shotgun with the loads for the critter.

Gunsmith died , but for years upon years we laughed about this. Yes there were a few more of these guns done, either for me or very close friends of mine whom thought as I did and no I will never share what that gun is, or what the heck we did.

Oh, I did this on more than one brand and action type .


Guns is/are still shooting, and whatever choke you want it to be "it is".


I am not bad - just consistent.

Steve

 

[sm]

Chokes are interesting, Still just part of the total sum of the Art and Science. Brister shares in one of his Chapters.

Stan Baker a good friend of Brister , maker of the Stan Baker Bore Diameter measuring tool is another great person to read up on.

Col B <something> name escapes me , Olin (like in Winchester) , John Browing , and others are a good something to read.

Names such as "Russian Choke" , Nicknamed for the choke the Russian Skeet team won the Olympics. Other names such as "Jug" and "Swage".

A LOT was done before screw in chokes came onto the scene. Lots of things going on besides "choke" in getting patterns and densities and , you name it.

Some important works I had on this and other subject burned in a fire, still , Lots of Art and Science to this Shotgun and its uses.

Steve