Rough forcing cone?

[philjones5]

Does anyone Know why some semi barrels have a very rough area approx half an inch at the end of the chamber? I don't know if its bad quality control or some kind of back boring, it looks like grooves milled in. I've seen it in Remington and Italian barrels

 

[VicW]

I have owned autos for many years and have never seen anything like you describe.

Something you can see down the barrel of a gas operated auto,in the vicinity of the gas chamber, is the gas port/s.

Next time you clean your gun poke a pipe cleaner or similar down the gas port/s and see where it comes out in the barrel.

Vic.

 

[philjones5]

Hi Vic,

No  the one I'm looking at is Inertia so no gas ports there, it almost looks like a very rough  thread!

 

[maddmatt]

You could be describing the forcing cones, typically this will be the first point of constriction  in the barrel and I believe is designed to allow breech pressure to build as the cartridge is fired. As the wad and shot goes past the forcing cone the resistance is felt as recoil. The cone will look a little like a ring in the barrel, they are usually rough from my experience and its the first thing I ask a gunsmith to lengthen and/or polish as this reduces felt recoil.

If this isn't what you are looking at I would get your gun to a gunsmith pronto

 

[philjones5]

Thanks for that, I'm sure now that's what it is, a polishing is in order!

 

[Will Hewland]

Thanks for that, I'm sure now that's what it is, a polishing is in order!

I suspect you shoot Eleys? They will cover forcing cones with a hideous rough layer..

 

[philjones5]

you're bang on Sherlock! Eley Superbs, Gamebores are mucky too

Good shooting

 

[Will Hewland]

you're bang on Sherlock! Eley Superbs, Gamebores are mucky too

Good shooting

Hull, express, rio, clever. Cut your cleaning time by forever..

 

[Emmsy]

pretty much all the remington barrels i have seen are very rough in the forcing cones, looks like they were cut with a step drill

 

[Hamster]

I once had the cones of my old spec 682 opened by a hand tool at some British Open while I watched and waited  , can't say the ended up with a mirror finish but they weren't that rough. My current one is not rough either.

 

[philjones5]

pretty much all the remington barrels i have seen are very rough in the forcing cones, looks like they were cut with a step drill

Do you think its bad quality control or could there be a purpose to it? maybe they actually intend it to be rough, can't imagine why maybe something to do with gas expansion

 

[Emmsy]

"Do you think its bad quality control or could there be a purpose to it? maybe they actually intend it to be rough, can't imagine why maybe something to do with gas expansion"




its a cheap gun, mass produced, you cant really expect something amazing

 

[dustin dick]

I remember an article in a well respected shooting publication when the tester showed that a less than smooth surface introduced to the forcing tapers, in both the choke section and forward of the chambers caused the pattern thrown to be improved beyond that of the unmodified arrangement. It would be a nice experiment for some of our techies here present to conduct.

 

[Emmsy]

tbh its not worth throwing money at a £50 barrel to see if there is any improvement in pattern, it already throws an 7" pattern at 20 yards, im not sure i need it any tighter

 

[philjones5]

I remember an article in a well respected shooting publication when the tester showed that a less than smooth surface introduced to the forcing tapers, in both the choke section and forward of the chambers caused the pattern thrown to be improved beyond that of the unmodified arrangement. It would be a nice experiment for some of our techies here present to conduct.

this is just what I was thinking, I find it odd that to have mirror finished barrels why leave a rough forcing cone? I'm beginning to think it could deliberate, looks like the cone is done that way after polishing

 

[Emmsy]

this is just what I was thinking, I find it odd that to have mirror finished barrels why leave a rough forcing cone? I'm beginning to think it could deliberate, looks like the cone is done that way after polishing

polishing a straight tube is a lot easier and quicker than polishing the tapered section, my guess is its just left that way