Making Barrels 'Oval' on the end...

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Oyeboten

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Had an old timer tell me once, that guys would sometimes form the ends of ('shortened' ) Shotgun Barrels into an Oval, in order for the Shot to spread out more horizontally.

This of course, for contexts of close-quarters defensive use.


Is there any truth to this do you s'pose?


Anyone here have any experience with this?
 
Possible, I suppose; there was an experimental "duckbill" choke used on some shotguns during the Vietnam War as a way of doing the same thing, but the pictures I've seen had internal ribs on it to strengthen the choke and split the shot charge up into discrete parts, instead of simply having the end of the barrel squeezed in. The trouble with these is that they restricted the shotgun to really only 1 load (buckshot) at fairly close range; if you could absolutely depend on that being the only circumstance under which you might need to use it, not a problem, but if you need a slug, or a longer-range shot presents itself, that's a real problem.

duckbillchoke.jpg
 
I will tell you what.....

I would much rather be seeing duckbills and diverters on the ends of shotguns than some of the C-rap I am seeing on some of these pistol grip jobs these days (read: Mossberg)

You would get actual tactical advantage with the A&W or Atchisson and not perceived coolness with a standoff device.

Interesting though that back in the day they were trying to figure out how to make the shot spread out faster and in a more predictable pattern and the rage these days seems to be to make the pattern tighter like the Vang Comp job. Pick your poison.

Also it would seem that as cool as diverters are (they are by the way) that they would take a backseat to aiming at your target. Right, equipment doesnt make up for incompetence. I would think this would be equally important in Vietnam as it is in a home invasion scenario.

And Lee,

I still wish someone would start making these things new production ;) I dont know if you followed the auction to its end but it did end up selling.
 
Last edited:
earl,

No, I didn't follow that one and don't know if it sold at that price or not.

More from the Wayback Machine-

According to Swearengen in _The World's Fighting Shotguns_, the US Air Force Directorate of Security Police in the mid-1960s developed a requirement for a spreader choke that would produce a wide elliptical shot pattern. This horizontal pattern spread was supposed to increase the hit probability from a shotgun on a moving target. Recall if you will that the Sixties were a time when the war in Vietnam was heating up, and civil unrest in the US was too. Lots of people in police and military circles were interested in many aspects of weapons both lethal and non-lethal. Shotguns came in for their fair share of attention, especially given their role at the time as the primary law enforcement long gun.

The Air Force request went to Frankford Arsenal for action, at the time Frankford was working on improvements to the military shotgun in general. Early experiments at producing a spreader choke were less than successful- the chokes split, patterned poorly and in various ways failed to produce te desired result. Ultimately Frankford ordnance engineer Charles A Greenwood developed the duckbill choke in answer to the Air Force requirement. It was subjected to a good deal of laboratory and field testing.

The original duckbill choke was simply a sleeve with a long V-notch cut on either side, the apex of the V toward the rear. The top and bottom of the sleeve were compressed toward the centerline at the muzzle, constricting the emerging pattern of shot in the vertical plane and forcing it to spread horizontally. The sleeve was permanently brazed onto the barrel so that it would not be blown off or rotated by firing the gun.

Early examples of duckbill- equipped shotguns were deployed to Vietnam in the hands of Marines and Navy SEALs. It was found that the open V- notches in the muzzle of the duckbill hung up badly on vegetation as the shotgunner tried to move through thick growth, so the duckbill was modified with a ring around its muzzle to exclude vines and branches. It was discovered that the spreader device worked as advertised, but in reality what was needed in a fighting shotgun was a way of producing dense, lethal patterns.

Spreaders in field testing produced patterns five feet high and twelve feet wide at 30 meters with #4 buckshot loads. At 40 meters, patterns were six feet high and sixteen feet wide. At 40 meters an average sized man would only be hit by a couple of pellets. But with a standard cylinder bored barrel shooting approximately a four- foot circular pattern at 40 meters, some 60% of the shot would strike an average man- sized target.

Still, the duckbill choke had its adherents, among SEALS especially. Development on the idea continued for several years. Clifford Ashbrook and Wilson Wing of Kexplore, Inc. in Houston, TX developed the A&W Diverter (pictured in my previous post) in the late 1960s using mathematical concepts, and received patent protection (# 3,492,750) in February 1970. The example I have is marked Patent Pending, I have no idea of its date of manufacture. It is an interesting artifact of a bygone era, I bought it as an oddity (and paid less for the barrel with the device installed than the spreader itself originally cost) and still consider it an oddity. I don't believe it to be practical save in very limited circumstances, but my preference for tight buckshot patterns should be pretty well known here.

Swearengen's last words (copyright 1978) on the concept of spreader chokes are: "It is expected that the controversy over spreaders and diverters will continue. It appears from available data that they will find little employment in actual combat."

lpl
 
People have experimented with ovaling the muzzle, but find out that it quickly gets battered back round by the impact of the shot.
Worse, the battering on the non-round muzzle can work harden the steel and cause the barrel to develop cracks.

The ring on the muzzle of the Vietnam "Duckbill" device was not to prevent entangling brush.
It was found that heavily used guns also started to batter the duckbill device out and caused the pattern to return to a circular one.
The battering also caused breakage of the device from metal fatigue.
The ring was added to prevent the muzzle from changing shape, but this also reduced the effect.
The duckbill was only usable with standard #4 buckshot and birdshot

Almost certainly the world's most experienced user of the duckbill device was famed founding member of the SEALs, Chief James "Patches" Watson, who wrote extensively about the gun and device in his book "Pointman".
He used it heavily during his multiple tours in Vietnam.
 
Interesting...thanks everyone.

I'd wondered about the battering...and, of course, no 'Slugs' if an 'Oval' end...


I've wondered also, about having a single, vertically oriented 'Julianne' cut on the Barrel's end...that is, having the end of the Barrel cut at an angle, like the end of a usual Hypodermic Syringe Needle is...which of course would slightly off set a spread to one side, but, may make a fairly horizontal emphasis...
 
Here are some pic's of the A&W I have on a test shotgun.

First up the diverter:
AW1.gif

AW2.gif

AWDiverter.gif

Pictures of hillmonkeys diverter made by a old WWII vet:

hillmonkey1.jpg

hillmonkey2.jpg

hillmonkey5.jpg

And another from fal308

fal308duck.jpg

fal308duck2.jpg

The A&W is the most advanced of the group I would say and can also fire slugs.
 
Hi DMR,



The first picture, the 'Diverter', looks especially interesting.


Is this an off-the-shelf product? Or..?


How do these various ones seem to print at say, 5 yards or 10?
 
Now the bad. At least with the A&W it does exactly what it was advertised for. Increase your chances of getting a hit:

7 yards #4 buck
aw7yrds.gif

15 yards, #4 buck
AW15yrds.gif

You would get a hit, but likely not take any of the three out of the fight.

Done again with 00 buck

7 yards
AW007yrds.gif

10 yards
AW00-10yrds.gif

15 yards(in the red circles
AW00-15yrds.gif

Again marginal reliablity in stopping the fight.


Compared to say this this
20vang00.gif

or this

20aimpro00.gif
 
Yes...


I had imagined these kinds of 'Chokes' for distances of 30 feet or less...so...looks like 5, 7, 10, even 15 Yards apparently, the one's you show, perform very well.


Past 15 Yards...one is soon better off without them.


So...the "A&W", is it a Commercial item then? Something one may buy?


The one made by the WWII Vet, looks to be 90 Degrees "off"...unless it anticipates one is going to hold the Shotgun, sideways...
 
IIRC there was something of that nature produced and aimed at the skeet shooting market some time back..... I'll look through some old books and see if I can find the article(s)......
 
So...the "A&W", is it a Commercial item then? Something one may buy?

They are no longer in production so far as I know from any vendor. I am aware of one company that is looking into it, but I think in the end they will skip it.

I got this one off of a board member and then had it installed.
 
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