Forcing cone angle in revolvers.

[Changeling]

I have read a lot of information on forcing cone angles on revolvers but since I joined this web site the only thing I ever seem to hear is 11 deg or 3 deg. I suppose that means something but I really don't know.

Wouldn't it make more sense to you to use a throat/forcing cone angle that corresponded to the bullets characteristics? Think about it.

Just a thought, my opinion.

[MakeMineA10mm]

I think the issue is that forcing cones in revolvers are out in the barrel vs right up against where the boolit sits in the chamber as on the rifle. Not only that, but the bullet must jump through the throat and the barrel-cylinder gap before it even gets there. AND, there's the issue of chamber alignment consistency with the bore (or lack thereof, depending on the revolver...)

There is the "Taylor throat" which is designed to more gently guide bullets/boolits from the cylinder's chamber throats into the bore, but to match the throat to a particular bullet falls short of bigger priorities such as the chamber alignment issue.

Just my thoughts. Others may weigh in with more analysis than I've done.

[Shiloh]

If my memory servers me correctly, 11 degrees is coming to mind. Can't recall anything about 3 degress.

Shiloh

[Multigunner]

When repairing a brass frame .44 revolver , I had to make a new arbor with oversized threads to replace the original which had pulled through, I freebored the first half inch of the barrel and tapered the lands for another inch. This seems to have greatly reduced the stress on the frame and improved accuracy.

I had one of the earliest Ruger Bearcat revolvers, and it blew lead in my face at every shot. It was also inexplicably inaccurate.
I checked the timing and it was dead on. Everything looked in order.
I returned the pistol to the store I got it from and never got another.
Only recently I found that a few of the first run of Bearcats had not had the forcing cone cut, and had slipped past Ruger's often rather lax quality control.
Had I known this at the time I'd have cut the cone myself, I really liked the feel of that little pistol.

[MT Gianni]

I remember 11 and 13 degrees but that isn't worth much. Too open a throat would increase blowby, IMO, and too small dis-forms it as it centers.

[Wayne Smith]

Gotta also think about the strength of the forcing cone. Take away too much metal and you can blow one.

[44man]

Gotta also think about the strength of the forcing cone. Take away too much metal and you can blow one.
I cut my SBH forcing cone to 11* when I first bought it back when the 10" silhouette model came out. It does not reduce the diameter at the rear, a go, no go gauge is used. All it does is extend the cone for easy entry of the boolit to the rifling. It only takes a few shavings to do it.
If the gauge drops in too far before cutting, it is not a good idea to cut at all.

[Lloyd Smale]

like 44man said the proper size for cast is 11 degrees.

[Changeling]

I cut my SBH forcing cone to 11* when I first bought it back when the 10" silhouette model came out. It does not reduce the diameter at the rear, a go, no go gauge is used. All it does is extend the cone for easy entry of the boolit to the rifling. It only takes a few shavings to do it.
If the gauge drops in too far before cutting, it is not a good idea to cut at all.

Jim have you got the tool for honing the cone and the go/no go gauge?

[44man]

Jim have you got the tool for honing the cone and the go/no go gauge?
I have the cutters and hone but not the .45 gauge, It is about $40.
I did not have to cut the .45, it shoots too good as is.
This is not a big worry part of a gun anyway unless the cone is off center or cut at some silly angle for the caliber.
I would relegate this process to the back room until you see what the gun does.

[Lloyd Smale]

once got a new ruger 45 colt blackhawk that didnt even have a forcing cone. That one and the one vaquero that had the crocked cut accross the top strap were about the altimate in quality control from ruger. My gun dealer buddy took the cake though when he got ruger bolt that had the barreled bored but had never even been chambered.

[Changeling]

I have the cutters and hone but not the .45 gauge, It is about $40.
I did not have to cut the .45, it shoots too good as is.
This is not a big worry part of a gun anyway unless the cone is off center or cut at some silly angle for the caliber.
I would relegate this process to the back room until you see what the gun does.

OK, whatever you say. If it turns out we need it I'll get it.

[leftiye]

They have the forcing cone cutters in 5 degrees too (even milder angle). I used this angle on my .327 smiff.

[Bass Ackward]

Forcing cone angles are relative. By that I mean that it simply needs to be in line and uniform and you will get used to operating with what you have.

No matter what you have, as the gun ages, the angle becomes more and more gentle requiring harder and then longer bearing area bullets to prevent the initial skid. So I don't want real shallow angles unless I have a short cylinder and cone.

If the jump becomes too long to where I have more impact velocity, then I want a steeper angle to help strengthen the drive band or I will get stuck shooting rocks. :grin: