Lengthened forcing cone

[Dungannon]

I hadn't heard of this modification before. Any of you guys had the forcing cone lengthened by a gunsmith, and seen the improvements claimed?

Shotguns: The Gunsmith Trick for More Pellets, Less Recoil

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[BWH]

used to shoot a lot of competitive trap. Had my rem 3200 cones lengthened, felt recoil went down considerably. Pellet count in a measured pattern is due to less pellet deformation, so there is some truth to more pellets!
Some barrels can be back bored/honed as well, this is kinda like shooting 12's in your 10ga.
Older guns were built with more metal than those of today, make certain you have a good base to work with prior to it being reamed out. I would be real hesitant on light weight models as an example.
A good smith will measure/mic the walls of the barrel, mostly to cover his backside from liability.

Off the top of my head, I would talk with Allison Carey gun works in SE pdx.

 

[DeanMk]

FYI, for anyone using a vintage break action shotgun, I don't think this is an issue, as the traidional choke for a shotgun is a Taper Choke, which essentially makes the forcing cone the choke.


Dean

 

[bivy53]

How might this affect the reliability of an inertial action?

 

[DeanMk]

I would think it would be easier on the mechanism, as the pressure spike would happen over a longer amount of time.
...that's what you're asking, right?

 

[bivy53]

So the pressure spike is lengthened, not reduced? My concern is that it might lose the ability to cycle lighter loads as it does now. My gun cycles everything from birdshot to buckshot, but if it's possible to improve terminal performance and reduce recoil without messing up cycle performance, I'm interested.

 

[Member 5605]

So the pressure spike is lengthened, not reduced? My concern is that it might lose the ability to cycle lighter loads as it does now. My gun cycles everything from birdshot to buckshot, but if it's possible to improve terminal performance and reduce recoil without messing up cycle performance, I'm interested.

If you gained 5% pellets and 10% reduction in felt recoil..... would it be worth it?

Maybe I'd consider it on a fixed action or pump but not a semi auto.

Not worth the possibility of added mods To support the work done so the fun cycles properly.

I too looked into the idea... consensus was no after the benefit would be if I shot a lot of trap/skeet it would reduce shoulder thump over a couple hundred rounds in a weekend/event.

 

[bivy53]

Yeah. The more I read, the more I think it may be kind of a gimmick. Think I'll pass for now. Might give it a go if I find an extra barrel down the road.

 

[DeanMk]

Here's what Randy Wakeman had to say about it, at Chuck Hawk's site...

One of the most highly touted features of a shotgun today is the mysterious lengthened forcing cone. Lengthened forcing cones have been touted to reduce recoil, give higher velocities, improve patterns and just about everything else you can imagine—perhaps giving us more miles per gallon as well. It falls into the category of what we like to call a "feature."

Features don't have to do much; in fact they don't have to really do anything at all. For a feature to be a "feature," it just has to exist. If it exists, it can be advertised. It helps if we can't measure the benefit of this feature easily, or at all. That way, no one can say we are wrong.

Shotgun makers like features. If they crow about it long enough and loud enough, then sooner or later they don't even have to pretend to know what it does, or state what it does. When they advertise it in big, bold letters, people assume it is a very good thing, otherwise they wouldn't make such a fuss about it.

That brings us to "Lengthened Forcing Cones!" or perhaps the more esoteric, "Precision-crafted, Highly Polished, Elongated Forcing Cone." They are about the same thing, of course, but we can ask a little bit more for our features if they take longer to say, or are harder to pronounce. "Cryogenic Elongated Forcing Cones" likely sell for a bit more.

When was the last time you saw a good shotgun pattern and rushed to measure your forcing cone? After someone shoots a good round of sporting clays, do people gather round and plead in hushed tones, "Could you tell me the length of your forcing cone, please?" What is the preferred forcing cone length of Olympic medalists, anyway? Somehow, that little bit of information never seems to make the news.

A forcing cone, of course, is the transition area from chamber dimension to the bore of your shotgun. The length is not really the point; it is the degree of taper. In theory, a more gentle taper is less disruptive to shot and wad. A short cone might be a bit under a half-inch section with a correspondingly sharp taper, where a long cone might be two or three inches or even longer. The beauty of a lengthened forcing cone is that we don't have to say what the length was before you lengthened it, or what it is now. This is particularly amusing in the case of brand new models, never before manufactured, with "lengthened" forcing cones. It forces the consumer to believe that they were going to make it with shorter cones, but erased that part from the production prints and then lengthened them. Even though they aren't any longer or shorter than they ever were, they only come one way, they are now lengthened because they could have made them shorter if they wanted. It is a lot like "room temperature," as no matter how hot or cold a room gets, it is still "room temperature."

Recently, I had a long session with one of top engineers in the industry, whose company has recently introduced a lengthened forcing cone on a couple of new models. After exchanging the usual pleasantries, the subject of forcing cones was breached. "You did some extensive R & D with these models, correct? A large quantity of shooting, carefully documented, with a variety of shells?" After being assured that this was indeed the case, with a great deal of time and money spent, I was told the new forcing cones gave beautiful and better patterns.

Naturally, I asked, "What can you show?" In other words, after all this R & D work, with a clean slate and the ability to use any forcing cone length you please, what is the documented benefit? A more even pattern? A higher percentage pattern? A 5% higher percentage pattern? 2%? 1%?

The answer was, "Well, no. We couldn't quantify any of that." I was a bit surprised. Nothing? No trend? Something perhaps with steel or other chaotic shot? Nothing with higher velocity loads, or higher payload loads? Nothing, not even an average of three pellets per shot increase in a 30 inch circle at 40 yards?

The answer was clear: "No, we couldn't find anything. The physics are sound, though, and it should work. We can say it doesn't hurt anything."

That is the crux of this biscuit. There are several approaches that sound good, or can at least be made to sound very good regardless of manufacturer or brand. In terms of tangible, real-world performance there is often nothing that can be reliably shown, or shown at all. In the case of elongated forcing cones, on the list of really important shotgun features of the day, it ranks very close to the search for Bigfoot. While we can't say that searching for Bigfoot will improve your shotgun patterns, we can confidently say that it doesn't hurt anything.

 

[bivy53]

Yeah, I read that earlier. Also found a lot of reviews in favor. I guess opinions, as they say, are like certain bodily orifices. Everybody has one. This seems to be something one has to prove through personal experience. I'll leave my good gun alone and maybe pick up an old single shot to try it on.

 

[DeanMk]

Yeah, I read that earlier. Also found a lot of reviews in favor. I guess opinions, as they say, are like certain bodily orifices. Everybody has one. This seems to be something one has to prove through personal experience. I'll leave my good gun alone and maybe pick up an old single shot to try it on.

Before you pick up that single, you might want to read THIS, as the same would apply, if that single has a fixed choke.


Dean

 

[DeanMk]

So the pressure spike is lengthened, not reduced? My concern is that it might lose the ability to cycle lighter loads as it does now. My gun cycles everything from birdshot to buckshot, but if it's possible to improve terminal performance and reduce recoil without messing up cycle performance, I'm interested.

1000 pardons, I just noticed that I never addressed your question.
It's the time that the pressure builds is what lengthens.
As the forcing cone is lengthened, the shot charge sees the transition from chamber to barrel interior in a more gradual fashion.
Thus the parts that make up the action see that pressure build more gradually as well, and that is better on those parts, rather than the "hammering" they would take if they saw the pressure spike happen "instantly".
Of course, we're only talking about mere milliseconds...maybe even fractions of a millisecond, so how beneficial all of this really is, might be almost moot.
Anyway, that's what I was getting at in my post about how lengthening the forcing affects the amount of time in which the spike occurs.


Dean