Lengthened Forcing Cone?

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Lengthened Forcing Cone?

Postby ksubigbuck » Mon May 22, 2006 7:22 pm

I was talking to my gunsmith the other day, and he suggested that I have the forcing cone on my shotgun lengthened. He said that it would cost $30 to do. What would be the advantages or disadvantages of this? Would it help patterns or velocity? He said that it would increase shot velocity, but I don't know if that makes sense to me or not. I don't see how it could. Thanks for your help guys.


ps -- the gun is a mp 153 if that matters
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Postby pennsyltucky » Mon May 22, 2006 7:28 pm

30 bucks is a good price if he will do it right and make sure it is honed and polished well.

http://www.gunnersden.com/index.htm.sho ... cones.html

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Postby Citori12 » Tue May 23, 2006 12:01 pm

Lengthening a forcing cone does not necessarily increase velocity. What it does is the same thing that the rave of aftermarket chokes do. Only its done first thing. The forcing cone is lenghtened to reduce the abrupt chamber change. This does 2 things first it allows a smoother transistion from the shot charge hitting the bore and it also reduces the amount for friction the shot column experiences when the round is discharged. My experience has been with hard non-toxic shot its a must. It increases pattern performance and reduces bridging. I do notice only a few fps increase in velocity but combined with a long choke tube I have experienced more even patterns. This also is a good thing for clay target guns as it reduces pellet deformation in lead shot. All my shotguns have 3" forcing cones and the improvement at the pattern board is worth the effort. Penny is correct make sure the cone is smooth and polished. For those who do not pattern thier shotguns and only determine its effectiveness in the field they may not even notice a difference. For me its essential for my shotguns.
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Postby Jim Broadbridge » Mon May 29, 2006 8:49 am

:withstupid: Best 30 bucks you could spend and may also reduce recoil a tad.
I'm not as good as I once was, but I'm as good once as I ever was.
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Postby tengoose1 » Fri Jun 09, 2006 9:55 am

:withstupid:'s both of em :toofunny: if done properly more to gain than lose, except on the velocity, never heard that one before?
I dont want to kill them all just the first one and the last one!
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Postby Citori12 » Fri Jun 09, 2006 12:19 pm

Any abprupt chamber change can effect velocity, as it does with rifles, because shotguns do not notice 24-50fps and most people do not chonograph shotgun loads there could very well be a better velocity performance. It is probably slight however. But what it really does is reduce drag and hard steel pellets from hitting the chamber change and causing the shot column all sorts of grief.

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Postby Sagebrush » Sat Jun 10, 2006 9:51 pm

So if I get this done to my 3" 12 Ga;

does that mean I can soot 3 1/2 " shells ??
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Postby Citori12 » Sat Jun 10, 2006 11:27 pm

Oh no no no no no! It changes the slope of the forcing cone is all, it does not change the chamber length. If you shoot a 3" gun now even if you rechamber for 3 1/2" you will find your shotgun will not handle 3 1/2" shells, because 3 1/2" guns have different recievers as well...now you may be able to rechamber a SXS or O/U for 3 1/2" shells but why? 3 1/2" guns require higher pressure specifications....Thus if you really need a 3 1/2" gun and do not already have one use the 3" guns you have and buy a 10ga!!! :thumbsup:
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