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View Full Version : Forcing Cone mods do what again?


9mmMike
September 2, 2001, 07:27 PM
I know we've been here before but......
I thought that lengthening the forcing cone was done to improve the patterning of a shotgun.
I just read that it reduces "felt recoil".
Which one of these things is true or is this one of those magic mods that does everything?
Mike

K80Geoff
September 3, 2001, 12:11 AM
The forcing Cone is the tapered area just in front of the chamber in a shotgun. It is the transition between chamber diameter and barrel diameter. Supposedly the longer and more gradual the taper the less recoil you should feel as the shot charge is gradually constricted as it enters the barrel proper. I imagine it would also help the pattern as less shot would be deformed causing fewer "Flyers". Deformed shot tends to open up the pattern.

So I guess both claims are correct:D


Geoff Ross

Dave McC
September 3, 2001, 07:15 AM
All of the above. The more gradual transition to bore diameter shortens the pressure spike, and the slow taper means less shot deformation,so less kick(tho it might take sensitive instruments to tell) and more pellets in the pattern. Pattern size stays the same, just has more pellets in it. Density, not spread, is improved.

9mmMike
September 3, 2001, 09:32 AM
Ah, excellent. The pattern stays the same but more dense (less flyers). This seems like a real benefit to me. I wonder why some Shotgun smiths advertise this service as a recoil reduction instead of a performance enhancement.
Thanks guys.
Mike

Dave McC
September 3, 2001, 12:00 PM
Because more folks are bothered by kick than are seeking optimum performance from their gun/load, Mike.

It's not talked about much, but one real reason the mag extensions, sidesaddles, taclites etc are so close to universal among practical shooters is the weight increase drops felt kick nicely.The same applies to gamer guns, a trap or SC gun will run heavier than its field equivalent. A 00 load from a 7 lb gun is an attention getter, even for those of us with good recoil tolerance, form and fit. The same load from an 8 lb gun is a pussycat.

Of course,doing the cone on an 8 lb gun still helps with the kick, but it's minor compared to the added mass's effects. Add a lb to a 7 lb gun, the felt recoil drops 14%. Doing the cone MIGHT drop the felt recoil 5%.Add those two and throw in a "Reduced" load like the Estate SWAT 00 some of us like, and you're talking maybe 25% less FELT recoil.

The HD 870 here runs close to 9 1/2 lbs. Kick is negligible, even with barnburner loads.

Frankenstein, my overpublicized parts 870, runs a hair over 7 lbs w/o the mag weight. 1 1/4 oz heavy field loads are noticeable, turkey loads can hurt with a bad mount or form. Add the weight and go to a 1 1/8 oz load, kick is much easier to deal with.

DML
September 4, 2001, 01:17 AM
One thing that I find interesting about this recoil reduction business is that small statured people seem to notice it more then bigger folks. I'm 5'8" and weight about 175 and I notice quite a difference between a stock barrel and one with the Vang Comp System. I have reports of women cops who couldn't qualify with the shotgun do great with a Vang Comped 870. On the other hand, I have seen big guys who said that they didn't seem to feel much difference.

I have switched back and forth between barrels with and without the forcing cone reamed and I notice at least a 15% reduction in felt recoil with the longer forcing cone. The difference is between a sharp jab and softer push. At least, that's how it works for me.

Dave McC
September 4, 2001, 04:06 AM
Dennis, this relates back to our discussion before. At 1/8 ton and 6'2", I'm not the best person to evaluate kick.

I've seen pixies do good work with shotguns. Not often,tho. Those little folks had above average drive and committment.

Small statured people are the folks that can benefit the most from the mods and addons.