Shotguns - Pictures of the effects of "choke"

[British Red]

On another forum, I was asked what different chokes do in a shotgun. I was "patterning" a shotgun today (shooting large sheets of paper to check the shot pattern) and a friend of mine took some pictures. I thought that since a picture tells a thousand words I would use a few to illustrate choke.

What are chokes?

In effect they change the speed at whch shot spreads by putting the shot through a narrowing "cone" at the end of the barrel.

There are varying amounts of choke from cylinder (no cone at all) to full choke (barrel narrows by 1mm)

In English designations. chokes graduate as follows

Cylinder
1/4
1/2
3/4
Full

In US These are
Cylinder
Improved Cylinder
Modified
Improved Modified
Full

The three photos below should show the effects. The large hole is made by the wad (a piece of felt or plastic that propels the shot down the barrel). All the shots were fired from the same gun, using the same type of cartridge, at the same range.

Cylinder (widest pattern)


Cylinder Choke by British Red, on Flickr

Half Choke (Modified)


Half or Modified Choke by British Red, on Flickr

Full Choke


Full Choke by British Red, on Flickr

As you can see - a cylinder choke lets the shot spread wide. This means that the shotgun pellets allow for a degree of "shooter error", but in a fairly short distance, the shot disperses. A full choke concentrates the shot, increasing the effective range but requiring great accuracy.

Using full choke on game at close range will make a great mess, but using cylinder on a distant target is unlikely to be effective.

As in so many things - its about the right tool for the job.

Hope that de-mystifies choke for anyone interested!

Red

 

[resnikov]

At what sort of distance were the shots taken?

 

[Deck]

Excellent information there Red. People often, in my experience, get caught up on chokes and don't know what to go for. Really sound information, and good advice for any new shooters: see what patterns different chokes throw out at a middle range

 

[ex-member Raikey]

Good demo Red,...

i used to use a Mosberg Varichoke for everything

a few times i,ve missed the first two shots, took a deep breath, wound the choke down tight, took a 3rd shot as the quarry hits the "reasonable distance"marker (about 40 yards for me,..hahah)

and took home supper with a closed eye 3rd shot,...

thanks for the info,...

Stu

 

[British Red]

At what sort of distance were the shots taken?

Fairly minimal - about 10 yards. This isn't designed to be illustrative of "game" range but rather to show the effects of a choke.

Patterning does involve lots of different ranges and seeing where there are holes in the pattern, how far the shot spreads and how different components (types of wad, amount of powder etc.) affect the pattern. It can even involve counting how many shot fall within a given sized area.

All a bit obsessive but a useful exercise with a shotgun so that things normally impossible to see are "made visible"

Red

 

[British Red]

i used to use a Mosberg Varichoke for everything

I still use a poly choke on occasions - something I am trying to understand is how it patterns compared to individual screw in chokes

We all talk about "range time" with airguns etc. to get good and understand ours (and the guns) capability. I'm lucky enough to be a member of a range that allows the same thing with shotguns - and fascinating it is too!

Red

 

[ex-member Raikey]

your lucky mate,...

plinking with an airgun, using different targets for effect is great,..trebor mints explode!! haha

And all too often i felt like letting loose and having a mess with the shotguns but as you know,..irresponsible to do so,...

using the smoothbore stuff on a range recreationally and being able to measure stuff like above is a good experience,...

 

[Rups]

Great thread thanks. I used to have an AYA No 2 which has 2 triggers allowing the firer to choose the choke. However I've now got a Webley which only has a single trigger. Should I choke a barrel? Which one, first or second? I've often thought I should use a choke and looking at your patterns I think I'm swayed that way.

 

[GordonM]

Nice one Red. In addition to the standard stuff, I use a Kicks Turkey choke and a Carlson's Dead Coyote choke, in my Benelli SBE. Both measuere .660 for the constriction. The Carlson's DC can be used with Hevi-shot and bismuth shot. For IDPA Defensive Multi Gun matches I use an 18 inch, cylinder bore, M870. I am a bit challenged with it if the slug targets get beyond 40 yards.

Gordy

 

[British Red]

Great thread thanks. I used to have an AYA No 2 which has 2 triggers allowing the firer to choose the choke. However I've now got a Webley which only has a single trigger. Should I choke a barrel? Which one, first or second? I've often thought I should use a choke and looking at your patterns I think I'm swayed that way.

Rups,

There will be choke on all guns.

On some guns the choke is built into the barrel (fixed choke) on others (generally newer guns), a set a of screw in chokes are supplied and the shooter can choose the choke for each barrel or even vary it for different types of shooting.

It is common to have different chokes on a double barrel so the shooter can quickly choose the best amount - 1/4 and 1/2 is common on game guns. Most single trigger guns like your Webley have a barrel selector switch which allows the shooter to decide which barrel fires first. Its often the same switch as the safety and can be moved left to right to select barrels and up and down for safety.

Hope that helps

Red

 

[salan]

Its funny, but when I used a full choke, I was a 'fair' shot. But then someone said that for game, I would be better with say a half choke (this was a single barrel gun). So I had the barrel changed to half choke. I never hit a damn thing with that gun after!
So I changed to another gun with full choke and started to hit things agin!
Alan

 

[British Red]

Alan,

I can understand that if going for shots at longer ranges - its quite possible for the shot to spreas sufficiently for quarry to be missed by a wide pattern.

BTW, I am not any kind of shotgun guru quite the reverse in fact - I am moving into shotgun after decades of shooting rifles - hence the patterning - its mainly about me being able to understand and visualise what the shot is doing - rather similar to calculating the "hold over" on a new rifle

 

[treelore]

good threat Red

 

[eraaij]

Very nice thread. Thanks for posting these. Steel shot, I presume? From a hunting point of view - It would be nice to see a spread pattern at 25-30 yards.

-Emile

 

[treelore]

i would have thought lead eraaij you use steel or bismouth on wildfowl

 

[British Red]

It was indeed lead

I'll happily do more fi people are interested. I did a few on same range and choke but different shot sizes on the last trip if people would like to see them?

Red

 

[treelore]

what shot size etc were you using ? 30grams No.6 ?

i would love to see some heavier shot used Red

 

[British Red]

32g felt wad 2 3/4" there

I'll sort the others in a sec

 

[British Red]

As requested some "real world" images of the shot sizes of various shotgun cartridges. One large hole on each target is caused by the wad (lump of felt or plastic that shoves the shot down the barrel).

First No. 6 Shot (bunny and bird sized shot)


Number 6 Shot by British Red, on Flickr

Next SG (known as buckshot in the US)


SG Shot by British Red, on Flickr

Finally Slug (or solid shot) - NB section 1 permission is required to possess solid shot


Slug by British Red, on Flickr

Hope thats illustrative

Red

 

[GordonM]

Great Stuff Red! Not to clutter this thread, but I did take this picture just for you Red. I was at the range Tuesday confirming my zero on my carbine for an upcoming match. The gentleman next to me, a brother veteran, was working with this...

Gordy