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Lengthend Cones on Shotguns
- Thread starter BILLDAVE
- Start date
charlie in md
New member
forcing cones
The forcing cone is the area of transition between the end of the chamber and the barrel itself. Think of it as a "funnel". Lengthening the forcing cone makes the transition more gradual, which in turn should reduce felt recoil, plus reduce pellet deformation. The cone is usually changed from about an inch in length to as much as 4-5 inches in length. Most gunsmiths that perform shotgun work offer this service, and some guns have that feature from the factory.
The forcing cone is the area of transition between the end of the chamber and the barrel itself. Think of it as a "funnel". Lengthening the forcing cone makes the transition more gradual, which in turn should reduce felt recoil, plus reduce pellet deformation. The cone is usually changed from about an inch in length to as much as 4-5 inches in length. Most gunsmiths that perform shotgun work offer this service, and some guns have that feature from the factory.
Thats about the size of it. I'll also add that the forcing cones that come from the factory on most of todays guns are not needed. Todays ammo dosen't need the short constricting forcing cones that the black powder shotguns, and the smokeless guns with cardboard wads needed.
Tell your friend to have a TRUSTED gunsmith do the work!!!
The cones must be lengthened, and then polished to a mirror shine.
Also, Browning Citori shotguns have chrome lined chambers and cones. A do-it-yourself "gunsmithing" job will ruin a reamer, and possibly a chamber...OR BOTH!
Tell your friend to have a TRUSTED gunsmith do the work!!!
The cones must be lengthened, and then polished to a mirror shine.
Also, Browning Citori shotguns have chrome lined chambers and cones. A do-it-yourself "gunsmithing" job will ruin a reamer, and possibly a chamber...OR BOTH!
I recently cut the forcing cones on 3 of my shotguns, two 870s and a 1100. Before doing it, I patterned them with various brands of 00B. After the cut, patterns tightened up about 25%. I didn't notice any reduction in recoil, but the greatest reduction in spread was with Reduced Recoil loads. Now i wish I had patterned the bird gun with #8 before the work, so I could see how it helped with that load...
On a similar note
I remember that some (OK, many) years ago someone was making shotgun barrels with a short (2-3") expanded area, maybe 0.010" over bore just before the choke. I haven't seen one for years, so maybe it wasn't such a great idea. Has anyone else ever heard of what I'm talking about? This was probably back around the '60s.
I remember that some (OK, many) years ago someone was making shotgun barrels with a short (2-3") expanded area, maybe 0.010" over bore just before the choke. I haven't seen one for years, so maybe it wasn't such a great idea. Has anyone else ever heard of what I'm talking about? This was probably back around the '60s.
mswestfall
New member
BILLDAVE
IIRC a Browning Citori with Invector Plus chokes comes from the factory backbored and with forcing cones lengthened.
It is an Invector Plus if it has chokes that stick out past the end of the bbl. You can also look for "Inv +" on the side of the bbls; on the polished steel just below the ejector (I believe on the left side).
I don't know this for a fact. But I did read it somewhere about 6 months ago.
Good luck.
IIRC a Browning Citori with Invector Plus chokes comes from the factory backbored and with forcing cones lengthened.
It is an Invector Plus if it has chokes that stick out past the end of the bbl. You can also look for "Inv +" on the side of the bbls; on the polished steel just below the ejector (I believe on the left side).
I don't know this for a fact. But I did read it somewhere about 6 months ago.
Good luck.
Newer Citori guns are back bored, but the cones are not factory lengthened.
Invector Plus tubes are for the backbored barrels, but they come in both extended and flush fit variations. Many field guns have the flush tubes.
The older Citori guns were not backbored, and take the standard Invector tubes. Most of these tubes were flush fit, and they interchange with Winchester, Mossberg and Savage.
Invector Plus tubes are for the backbored barrels, but they come in both extended and flush fit variations. Many field guns have the flush tubes.
The older Citori guns were not backbored, and take the standard Invector tubes. Most of these tubes were flush fit, and they interchange with Winchester, Mossberg and Savage.
perazzimx14
New member
Biggest wastes of money people spend on shotgun barrels
1. Porting
2. Back-boring
3. Lengthing forcing cones
4. Ported choke tubes
5. Hi viz sights
Spend the money that you would spend on the barrel work and buy shells and targets. You will be a better shot. Barrel work IMHO is "snake oil".
If you want to reduce recoil either shoot a lighter shell or add weight to your gun.
1. Porting
2. Back-boring
3. Lengthing forcing cones
4. Ported choke tubes
5. Hi viz sights
Spend the money that you would spend on the barrel work and buy shells and targets. You will be a better shot. Barrel work IMHO is "snake oil".
If you want to reduce recoil either shoot a lighter shell or add weight to your gun.
mswestfall
New member
I would move back-boring to the bottom of your list.
I think it does two things:
It makes a bbl easier to clean
It lengthens the life of a "poorly cleaned" (averagely cleaned) bbl
I think it does two things:
It makes a bbl easier to clean
It lengthens the life of a "poorly cleaned" (averagely cleaned) bbl
While I do not see the need in forcing cone and backbore work, I will not refute its ability to affect the patterning of the shotgun. Run a Vang for a little while, and you will see. For me, its not worth the expense, as my 870 shoots the TAP buck as well as I can expect it.
I've had a few cones lengthened. On a chokeless 870 barrel, one brand of buck shot patterns about 4" tighter at 25 yards.
Another upped density by close to 10% using a trap load of 7 1/2s.
A long cone mimics about one degree of choke. One can get the same effect by switching to the next larger shot size or using premium shells.
I can feel no difference in recoil.
IMO, long cones are for when 99/100 simple isn't good enough.
Meanwhile, buy ammo, use up, repeat ....
Another upped density by close to 10% using a trap load of 7 1/2s.
A long cone mimics about one degree of choke. One can get the same effect by switching to the next larger shot size or using premium shells.
I can feel no difference in recoil.
IMO, long cones are for when 99/100 simple isn't good enough.
Meanwhile, buy ammo, use up, repeat ....