Shotgun barrel length and chokes.

Double barrel, side by side, over-under, semi-automatic, straight-pull and lever action shotguns.

Re: Shotgun barrel length and chokes.

Post by rc42 » 21 Sep 2021, 7:51 am

TheLoff02 wrote:So let me ask then … for my first shotgun, initially for club practical Comps - would an 18” be suitable?
And would be appropriate for hunting, suitably loaded, at about 20m (as per the Qld rules, although I’m in Vic. )…?
Thanks in advance


Check with your club, some clay shooting clubs don't allow barrels below 28" or even pistol grip or magazine fed shotguns, in terms of shot spread the choke matters far more than the barrel length and muzzle velocity/energy would likely be very similar whether the barrel is 20" or 30".

Longer barrels give a better sight radius from your eye to the front bead and the extra barrel weight slows and smooths movement when tracking targets and pulling in front of them so are preferred for clays. For hunting the shorter barrels are often better as it's easier to maneuver them through scrubs and bushes.
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Re: Shotgun barrel length and chokes.

Post by boingk » 22 Sep 2021, 9:39 am

Research from Remington says all powder in commercial cartridges is burned within 15-18" of the barrel.

Practical observations from Paul Harrell of Youtube fame show that a 20" gun gives up approximately 100fps to a 30" gun with the same ammunition, so a 1300fps cartridge in a 30" becomes a 1200fps with the shorter gun.

If you're serious about a first gun get something cheap and basic. Your local will likely have a stack of 12G Boito/Stoeger guns in over-under or side-by-side. They are good basic things and will let you get a feel for what you like. They are generally choked improved cylinder and modified or modified and full. Sometimes there are other combos but those are the main in fixed choke guns from what I can gather.

Choke spread will not be derivative of barrel length. Choke is a simple barrel restriction, a funnel if you will, sending the shot into a tighter pattern downrange.

Cylinder will generally group 40" at 25m, improved will go to 30m, modified 35 and full 40m with the same spread.

This will vary gun to gun and choke to choke so it's important to pattern your gun. Load will also make a difference, heavier shot tends to fly straighter.

choke_on_shot.jpg
choke_on_shot.jpg (48.37 KiB) Viewed 2873 times
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Re: Shotgun barrel length and chokes.

Post by LawrenceA » 22 Sep 2021, 1:40 pm

Here is my 2 cents.
Choke is not influenced by Barrel length.
But Choke is technically not a fixed restriction. Full choke is the amount required such that any further restriction does not tighten the pattern.
Barrel length can influence the handling and efficiency of combustion. But velocity can influence pattern. A slower load will theoretically produce a tighter pattern.
PS Buckshot at 40 is ludicrous. It is the same as shooting a pig with an inaccurate 22 a few times.
One well placed shot is all it takes.
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Re: Shotgun barrel length and chokes.

Post by boingk » 22 Sep 2021, 3:38 pm

CAVEMAN wrote:Just a play thing at the moment, but hopeful more so for pigs or similar... Id ultimate like to get a decent pattern at 50m that would be suitable with buckshot or smaller depending on target.


Hey mate, didn't see the above. 50m is very, very optimistic for anything but a known quantity of heavy shot/slug. Lets get into shot sizes - a slug is usually around the 1oz / 28g mark. You can get all sorts, but 7/8oz or 1oz are most common. They're usually reasonably accurate to about 50m but you need to get a combo that works with your gun. By 'accurate' I mean you'd likely be able to hit a stationary pig sized target if you have patterned your gun beforehand with that load. Obviously you're going to leave a nice big hole in whatever you hit as most slugs designed to work with a shot cup are around the .680" diameter. Casting your own and reloading target shells is a cheap way to make slug rounds, by the way.

Now onto shot. '00' Buck / 00-SG is .33 calibre and '000' Buck / LG is .36 calibre. You'll get roughly 8 or 6 (respectively) in a modern cupped 12G round of 2 3/4" length. This varies with manufactuer and cup design. Youre going to be looking at these for pigs IMO.

#2 Buck / SSG is a .27 calibre ball and #4 Buck is a .24 calibre ball. Even close up I wouldn't go smaller than a #4 Buck or you're likely to have a big, angry pig turn on you. Most people would say this is on the small side, too, unless you're right on top with a modified or full choke to tear a ragged hole into something. You'll get about 20 #4 balls in a standard shot cup, again depending on design may be less or more.

The thing with patterning your shot is that once it starts to spread you will end up with gaps in the pattern. The less balls of shot you have the bigger the gaps. At a certain distance the gaps will be large enough that your target animal may be missed completely, and ideally you want at least a few on target. You can go to more of a smaller shot, but depending on the game you're after it may not be effective on it so (assuming you're already using a full or tighter choke) you're just going to have to move closer.

And the birdshot? Well, you have a ton of small pellets that you want to disperse rapidly because you're shooting at small rapidly moving targets. You don't want a tight shot pattern in close or you'll blow the thing to smithereens and have nothing left for your effort... assuming you want to use the game for meat. If not, load and choke however you want. For reference, the common 7 1/2 target shot is about a .090" ball and theres 410 of them to the ounce. This goes to #7 / .095" / 350 and #6 / .102" / 270 for the common shot sizes. Aussie BB's are about .16" with 72 to the ounce.

You can buy target shells cheaply and reload with whatever shot/slug you want to good effect, just remember to pattern before taking to the field! See TAOFLEDERMAUS on youtube for more of this kinda thing.

So, thats shot in a nutshell. Happy hunting 8-)

- boingk
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Re: Shotgun barrel length and chokes.

Post by boingk » 22 Sep 2021, 3:54 pm

LawrenceA wrote: Full choke is the amount required such that any further restriction does not tighten the pattern.


Lets not confuse the guy.

Cylinder - No restriction
Improved - .010"
Modified - .020"
Imp. Mod - .030"
Full Choke - .040"

Those are the industry standards. Patterning your gun will reveal where you want to be with a given load. Beyond a point some chokes may be detrimental to the desired pattern.

You can get others, too, like 'Skeet' which is often .005" restriction, and 'Extra Full' or 'Turkey' chokes which can be as much as .060" restriction. Typically these are for specialist applications and not all that relevant to the beginner, or dare I say most typical hunters.

I agree with the rest of what you said - velocity can and does impact pattern at distance, and buckshot at 40m is probably optimistic for all but the best dialled-in combinations. Some modern loads (Federal 'Flite Control' Buckshot comes to mind) give exceptional grouping at what would traditionally be considered extreme range. I've seen roughly dinnerplate sized groups of shot at 35~40m.

Here's a test with standard Buck and 'Flite' Buck at 10 yard / 30 feet. He uses a few different guns, too, and its interesting to see the effect on each load.

https://youtu.be/EVKfIAa9lbk?t=64
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Re: Shotgun barrel length and chokes.

Post by MtnMan » 17 Jun 2022, 4:51 pm

Been patterning my new Adler B220 20" barrel. I'm settling on the full choke.
The Improved cylinder choke is about useless past 15m with 4 shot and BB. Rabbits/foxes could slip through the pattern.
Improved modified choke brings it out to about 25-30m.
Full choke is the only one acceptable past that.

SG's are pointless past 20m even with full choke. Pigs might get hit in the head or the foot, maybe both if your lucky.
SG with Imp cylinder was useless even at 15m. Might be OK if you wanted to stop a croc eating your outboard.

Full choke #4 pattern at 15m was about 10"-12" diameter
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Re: Shotgun barrel length and chokes.

Post by Blr243 » 17 Jun 2022, 6:38 pm

Good to see people patterning their shotguns. It’s as important at sighting In Your rifle .. u need to know where the lead is going
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Re: Shotgun barrel length and chokes.

Post by JohnV » 17 Jun 2022, 7:42 pm

I would be getting a shotgun with changeable chokes and at least a 26 inch barrel . What people don't think about is that all shotgun loads are designed to work in 26 to 30 inch barrels not 20 inch . So you could loose some velocity especially with the slower shotgun powders . I went shooting once with a guy who had a 20 inch coach gun and it was fairly useless . My Breda 5 shot auto with the full chock tube fitted had way more range and downing ability .
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Re: Shotgun barrel length and chokes.

Post by JohnV » 17 Jun 2022, 7:51 pm

MtnMan wrote:Been patterning my new Adler B220 20" barrel. I'm settling on the full choke.
The Improved cylinder choke is about useless past 15m with 4 shot and BB. Rabbits/foxes could slip through the pattern.
Improved modified choke brings it out to about 25-30m.
Full choke is the only one acceptable past that.

SG's are pointless past 20m even with full choke. Pigs might get hit in the head or the foot, maybe both if your lucky.
SG with Imp cylinder was useless even at 15m. Might be OK if you wanted to stop a croc eating your outboard.

Full choke #4 pattern at 15m was about 10"-12" diameter

I invented a load called a BeeGee . It consisted of a 1- 1/4 oz Winchester mono-wad with three SG pellets jammed into the base and the remainder of the load filled with BB shot . When fired through a full chock the BB shot buffered the SG pellets and kept them near the center of the pattern most of the time .
It could take anything , foxes , goats , pigs , deer , at normal shotgun ranges .
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Re: Shotgun barrel length and chokes.

Post by bigpete » 17 Jun 2022, 8:58 pm

I did a load of 6x .375 round ball buffered by size 4 shot
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Re: Shotgun barrel length and chokes.

Post by MtnMan » 17 Jun 2022, 9:17 pm

What does the pig say when it gets hit with BeeGee shot?

"Huh huh huh huh, Not stayin' alive, not stayin' alive"
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Re: Shotgun barrel length and chokes.

Post by bigpete » 17 Jun 2022, 9:26 pm

MtnMan wrote:What does the pig say when it gets hit with BeeGee shot?

"Huh huh huh huh, Not stayin' alive, not stayin' alive"


Oh god no.....it hurts
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Re: Shotgun barrel length and chokes.

Post by animalpest » 18 Jun 2022, 11:45 am

:lol: :lol:
Professional shooter and trapper
Trainer and consultant
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Re: Shotgun barrel length and chokes.

Post by Border_Bloke » 23 Jun 2022, 10:49 am

JohnV wrote:I invented a load called a BeeGee . It consisted of a 1- 1/4 oz Winchester mono-wad with three SG pellets jammed into the base and the remainder of the load filled with BB shot . When fired through a full chock the BB shot buffered the SG pellets and kept them near the center of the pattern most of the time .
It could take anything , foxes , goats , pigs , deer , at normal shotgun ranges .


Reminds me of the old "buck and ball" and "foraging" loads they used in muzzle loaders and later, in the 45/70 in the American civil war. The bottom article has a few references to these in the 45/70.

https://en.wikipedia.org/wiki/Buck_and_ball
https://www.shootersforum.com/threads/45-70-3-ball-load.48882/
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Re: Shotgun barrel length and chokes.

Post by JohnV » 23 Jun 2022, 7:20 pm

bigpete wrote:I did a load of 6x .375 round ball buffered by size 4 shot

That's the same concept as my loads . Except 4 shot is a bit light for me and buffering with BB takes out foxes and small pigs . One time shooting along an irrigation ditch with just straight BB loads I dropped a few smaller pigs but to my surprise one pig went down with just three BB shot to the head no other hits that I could see . That was a bad shot on my part but the edge of the BB pattern still got him .
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Re: Shotgun barrel length and chokes.

Post by JohnV » 23 Jun 2022, 7:24 pm

Border_Bloke wrote:
JohnV wrote:I invented a load called a BeeGee . It consisted of a 1- 1/4 oz Winchester mono-wad with three SG pellets jammed into the base and the remainder of the load filled with BB shot . When fired through a full chock the BB shot buffered the SG pellets and kept them near the center of the pattern most of the time .
It could take anything , foxes , goats , pigs , deer , at normal shotgun ranges .


Reminds me of the old "buck and ball" and "foraging" loads they used in muzzle loaders and later, in the 45/70 in the American civil war. The bottom article has a few references to these in the 45/70.

https://en.wikipedia.org/wiki/Buck_and_ball
https://www.shootersforum.com/threads/45-70-3-ball-load.48882/

That's interesting . I never knew that .
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