The perversion of shotgun barrel length

[Wapiti]

Can I get some help from the shotgun shooters out there on a question I have?
Why do some shotguns have 28, 30, 32" barrels?
Is it solely the sighting plane length? And is it a myth?
I mean, it's not like a rifle where you align the front and rear sight for precision. There is no rear sight on fast aiming shotguns.

I ask because of this observation of my own use case.
My wife has a Buckmaster PB12-M. It's got a 16" barrel, and is super-short overall, great for stashing or tight situations.
It was not bought to shoot clays. It was bought for around the farmhouse at night, for things that go bump.
It is extremely simple to use from a repeating shotgun perspective for multiple shots, in cat A & B anyway.
It has screw in chokes with it, to adjust the pattern I imagine.
With a full choke, and 9-pellet buckshot, the groups are so tight at house long hallway length, the hole is one hole from all nine pellets.
With the more open chokes, the pattern opens up like the cylinder bore of my Remington 870 pump.
It has a green dot reflex sight that turns on when you pick it up.

So I guess what I want to know is, Does barrel length make a better tighter pattern at a given distance? Because from what I see, the pattern at a given distance when choked the same is pretty much identical to a 30" barrel O/U Beretta.
But the sight radius has been changed from a cheek at one end, a tiny steel dot at the other, to a dot that has no parralax to throw you off.
So why the mega long barrels? That long sight radius?

[Zach]

I believe it's largely to smooth out the swing when tracking birds or clays that travel in a predictable path. When you've got the gun moving in an arc, having some mass out away from the pivot (you) will diminish the effect of muscle twitches and inconsistencies

[No1Mk3]

Barrel length makes no difference to pattern, that is solely a consequence of velocity, wad type and choke. Some ammo gains from a longer barrel, but every test I have seen seems to indicate max velocity by about 26". I really don't feel barrels longer than this add anything at all other than perhaps sighting.

[Wapiti]

Thanks for the replies fellas. Yeah, it's gotta be the open-sight plane and fit, and the swing consistency and follow-through I guess.
Something I am completely inexperienced at doing. I never shoot into the air.
The fact that I do OK at our farm shoots is just plain arse.

I guess that velocity could be chrony'd, but I wouldn't use an old screen type chrony. Wouldn't make it through the session i'd reckon.

[Fester]

Yeah, it's a debate that will go on forever.
As said, it's just the 30'' for swinging on birds and clays.
20'' for a great brush gun for pigs, snakes, or anything up close.

Patterning and testing whatever shot you use is the key.

The only personal results for me was the 20" Dicko did hit some clays, surprisingly.
It also shot slugs with more accuracy than I ever expected.
I used the choke that was 1 size tighter than open as a bloke did all the testing, and was keener than me.
He used a scope and shot it from a bench lol
I put a smaller Bushy red dot on and leaned against a pole.
The red dot gives me an OK cheekweld, but hard to see in sunlight so not that great.

It has been a safe queen, but I love it as a handy light shotty.
I would love to shoot a meaty deer with it before it gets crushed with so little use.
I tried once, left the pack in the car and carried the Tikka on the shoulder.
You guessed it, seen deer at about 200 and used the deer rifle.

[Wapiti]

Each to his own hey.
That's what I found too, I'd rather have an open-sighted powerful pump rifle like a 7600 than a shotgun, there's more chance I will catch up with a predator animal at 100 yards plus that will cause me heaps of financial losses and heartache if it's allowed to run off because I have a "cool" shotgun that hasn't the reach.
Taking that one further, an accurate powerful rifle like that with a 1-8x scope becomes just as fast in a scrubby creek at 1x but can put a bullet between the eyes of a dog at 150m on 8x. Or in the chest at 200 plus.
I can see how shotguns can be great fun when the overall results aren't coming out of your own pay packet. Having another go later is not on the menu, hey it's the main factor in why there are category D rifles licensed instead.

[mchughcb]

Can I get some help from the shotgun shooters out there on a question I have?
Why do some shotguns have 28, 30, 32" barrels?
Is it solely the sighting plane length? And is it a myth?
I mean, it's not like a rifle where you align the front and rear sight for precision. There is no rear sight on fast aiming shotguns.

I ask because of this observation of my own use case.
My wife has a Buckmaster PB12-M. It's got a 16" barrel, and is super-short overall, great for stashing or tight situations.
It was not bought to shoot clays. It was bought for around the farmhouse at night, for things that go bump.
It is extremely simple to use from a repeating shotgun perspective for multiple shots, in cat A & B anyway.
It has screw in chokes with it, to adjust the pattern I imagine.
With a full choke, and 9-pellet buckshot, the groups are so tight at house long hallway length, the hole is one hole from all nine pellets.
With the more open chokes, the pattern opens up like the cylinder bore of my Remington 870 pump.
It has a green dot reflex sight that turns on when you pick it up.

So I guess what I want to know is, Does barrel length make a better tighter pattern at a given distance? Because from what I see, the pattern at a given distance when choked the same is pretty much identical to a 30" barrel O/U Beretta.
But the sight radius has been changed from a cheek at one end, a tiny steel dot at the other, to a dot that has no parralax to throw you off.
So why the mega long barrels? That long sight radius?

Shouldn't make much difference on patterns, thats more to do with chokes, shot size and weight. 32, 34 etc are best left for competitions. Yes there's more weight and the swing through is less disturbed as you fire. However like a lot of things, people buy stuff, want a jack of all trades, use it for what it wasn't intended and complain. For most hunting birds or foxes I'd recommend 26" to 30". I've seen 32" used and its a pain the arse because of its length to put in the backseat. I've seen 20" barrels that are the worst of swing but easy to throw on the backseat or sit with on the passenger seat.

[Fester]

I found no great difference with the patterns when I compared the Dicko 20" and my Silver Pigeon 30"

It was limited to birdshot at a clay field test plate from a few common distances.
Enough for me to conclude there is not much difference from the barrel lengths, and shotty range is pretty short anyway.
Slugs would be needed for anything longer, as they go well.

Not a chance that blokes using buggies and utes would want a long gun.

Shooting suckers after taking big pigs out would be a job where a shotty would be king.

[Wapiti]

I just posted an answer too and it disappeared. Weird.

On the swing thing, not too long ago I was asked to come out and have a look at a Bentley 28" pump shotty that had been discovered in a disused shears quarters.
I had that short mag tube underneath, was supposed to be a 5-shot but only took 4 in the tube mag of quite-short-for-length 2-3/4" Federal Buckshot.
Stuff carrying the 5th on the chamber, loaded, what a disaster waiting to happen.
Anyway on swing, the thing swung and pointed like an 8-foot star picket. Once I got a swing going, it was tempting to continue for a 360' circle.
Who's idea was that to make something that was such a monstrosity.