Relieving Chamber Cones?

[Theodore LeDurt]

Is relieving chamber cones the same thing as lengthening the chamber? I have a 10ga with 2 5/8" chambers which will not allow a Gauge Mate (10ga to 12ga) insert fit in my gun. To alleviate the problem I'm considering lengthening out the chambers to 2 7/8", but saw in a book the term relieving chamber cones and was just wondering if this is the same thing?

Thanks for any help.

[Rick Losey]

no in simple terms

the chamber is the area for the shotshell - this decides the length of the shell for that gun.

the forcing cone is the transition area from the chamber to the barrel.

relieving forcing cones on their own is I believe generally done to reduce felt recoil and improve pattern

the forcing cones would be altered if the chamber is lengthened,

[Theodore LeDurt]

The term used in Diggory Hadoke's book. "Vintage Guns For The Modern Shot", uses the term "relieve chamber cones", unless this is the English term for forcing cones, I was talking about chambers, not forcing cones.

[Robin Lewis]

Here is an interesting writeup on the topic which addresses the older shotgun designed for paper shells using fiber wads and the modern shotgun made for use with plastic shot cups.

http://www.gunreports.com/special_reports/long_guns/Older-Shotgun-Chamber-Maintenance155-1.html

[Fred Preston]

I simply shortened the 10/20 guagemates for my 10ga. lifter with 2&5/8" chambers with the step to bore diameter. The 20ga. empties push out easily and could be reloaded. If I had it to do over, I would just reduce the OD of the last 1/8" of the guagemate to bore diameter.

[Theodore LeDurt]

After shortening the Gauge Mates, my shells expand beyond the end of the Mate, and are hard to remove. That is why I want to lengthen chambers, so the Gauge Mates will work without being modified. Temporarily I am shooting RST 2 1/2", as they come out without issue.

[charlie cleveland]

i shortened one of my ga mates also have trouble getting hulls out ut cut me a wooden dowel and use it to punch out the hulls..cheap but effective... charlie