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View Full Version : Lengthening Forcing Cone



Golden2Hunt
12-11-2009, 11:30 AM
Just want to get some opinions on the effects of lengthening the forcing cone on my Benelli M1. A local gunsmith will do for $70. Wondering if it is worth it.

http://www.odenthalgunsmithing.com/services.html

Per his web site:
Helps to reduce recoil. Improves the pattern up to 15%. Allows the shot to leave the shell and enter the barrel much more gradually which results in less deformed shot.

If it makes that much of a difference why don't manufacturers do it?

1stout
12-11-2009, 12:20 PM
Many gun makers already do it. Beretta lengthened theirs on the 391 a couple years ago. I think they did some other changes as well and called it the optima.

birdshooter
12-11-2009, 02:44 PM
Odenthal has a good reputation. I would ask his personal opinion of it. I'm sure he will tell you whether it would make much difference.

In theory it would seem longer cones would ease the shot into the bore gradually as apposed to abruptly to lesson recoil and maybe improve patterns a bit. There is a point of no further gain and I think the experts have determined that anything over 2" will yield no further improvement. Most of the newer shotguns these days are coming with longer cones from the factory. So adding more length is pointless.

How much of a difference will make? Truthfully you may not be able to feel the difference in felt recoil even if you could somehow measure an improvement. Same goes for patterns. Yes, it may be a bit more uniform, but how much. If you read anything from some of the industry leaders in shotgun modifications (Briley, Ballistic Specialties etc..), many will say if they could only do one mod it would be lengthened cones. Even so, I think the improvements are minimal at best. Adding gun weight will do more for felt recoil then longer cones.

I have a couple Beretta Autoloaders. An older one that I had the barrel ported and the forcing cones lengthened. The newer one is bone stock. I shoot each as well as the other and both pattern pretty well with the factory chokes. Enough so, that I can not really tell much of a difference without scrutinizing the patterning board. Granted those are two difference guns and unfortunately I did not do a before/after pattern session on older gun to make any comparison. Recoil wise it is a unfair comparison as one is a half a pound or slightly more on the lighter side.

On a field gun, personally I would not have it done. But that's just me. But if $70 isn't an issue for you then go for it.

FWIW

Golden2Hunt
12-11-2009, 04:21 PM
Thanks for the info. Birdshooter - This is what I was hoping to get in a reply. Someone who has the same gun, one with a lengthened forcing cone and one without. True, the ideal test would be a before/after test but your comparison is pretty close.

After my original post I did a search and found this article. http://www.chuckhawks.com/shotgun_mysteries.htm

He brings up a concern about the coating in the barrel. I think I am not going to have it done for this gun. Hopefully I can afford to buy a new gun this summer, which will make my M1 a backup. I'll inquire about the forcing cone when shopping.

I also agree, Odenthal was recommended to me by a friend who does a lot of shooting.

bobeyerite
12-11-2009, 04:47 PM
Goldy, there is one real good question to ask yourself. How am I shooting with the gun now? If the answer is very few problems, then why do something you can't reverse. I'm for leaving the gun alone and just have fun with it.......Bob

birdshooter
12-12-2009, 07:51 AM
This is what I was hoping to get in a reply. Someone who has the same gun, one with a lengthened forcing cone and one without. True, the ideal test would be a before/after test but your comparison is pretty close.

Just to clarify, they are not identical guns. One is a 23 year old A302 and the other is a 391 Urika2. The Urika 2 391's are coming these days with longer cones and back bored barrels, whereas the 302 does not. Just another testament that barrel modifications to the newer guns are not necessary IMO. Some of the older Brownings and Beretta's/Benelli's (over 15 years old) would probably not have these modifications as well, so if you wanted to experiment an older gun would be my choice to do so.



I also agree, Odenthal was recommended to me by a friend who does a lot of shooting.

He know's his stuff.

3goldens
12-14-2009, 12:17 AM
I did exactly what you described to my Rem 1100 3" mag, as well as had the fixed full choke taken out to a modified. Made a world of difference shooting steel for ducks and geese. I dusted it off recently for a duck hunt and found that I no longer shoot it quite as well as my Benelli but I suppose I could get back in the groove with a few rounds.

jnormanh
12-14-2009, 08:16 PM
It seems pretty much nonsense to think that lengthened forcing cones reduce recoil. If a load of shot leaves the barrel with X ft-lbs of energy, then the recoil must be exactly X, regardless of what has happened in the barrel.

Unless someone changed the laws of physics while I wasn't looking -

For every action there is an equal and opposite reaction.

1stout
12-14-2009, 09:37 PM
J,

Before you go thinking you know more about physics than everyone else you should know that when shooters talk about reducing recoil they are talking about felt recoil. There are a lot of things that people do to reduce recoil, an example of a few are butt pads, slower burning powder, paper hulls, porting the barrels, etc.

jnormanh
12-14-2009, 10:09 PM
J,

Before you go thinking you know more about physics than everyone else you should know that when shooters talk about reducing recoil they are talking about felt recoil. There are a lot of things that people do to reduce recoil, an example of a few are butt pads, slower burning powder, paper hulls, porting the barrels, etc.

Lighten up 1stout. My Physics education stopped at Physics 102. I do, however, know the different between felt and measured recoil, neither of which is influenced by forcing cone length.

birdshooter
12-15-2009, 08:53 PM
J,

There are a lot of things that people do to reduce recoil, an example of a few are butt pads, slower burning powder, paper hulls, porting the barrels, etc.

You forgot possibly the biggest difference maker of all, WEIGHT......

add a few ounces here and there and you will notice less recoil.