Terminology of barrel "cone"?

E

Elerius

New member
I have been thinking (for deep into the future) of making a VERY custom built revolver, and I'm all about aesthetics being just perfect. There is a bit of terminology that has escaped me. In this picture:



What exactly is the conical tapering from the front of the frame going down the barrel for that first inch or so supposed to be called? Part of the forcing cone? I had always thought it was a normal requirement of having a tapered barrel but in peering closely at pictures, it seems like it only exists on some guns and not others, tapered, bull, straight, or otherwise termed. The M19 is straight from the frame, is this not a tapered barrel?
 
That is barrel tapering. Forcing cone is the mouth of the barrel where the bullet jumps from the cylinder to the barrel. you can see it when the cylinder is open.
 
That type of barrel serves two purposes. It puts more strength at the rear of the barrel, and it provides a good shoulder for setting up the barrel and providing a crush fit to keep the barrel from rotating. That older gun is "pinned" meaning that in addition to the shoulder, it also has a cross pin in the frame to prevent barrel rotation, a feature S&W has discontinued.

The taper, obviously, reduces the weight of the barrel, a necessity for a practical carry revolver.

Jim
 
If it were a rifle and if you were British it would be a "reinforce" or maybe a Knoxform. But it isn't and you probably aren't, so it is just part of the tapered barrel profile.
 
I thought the Knoxform (orignally "Nock's form") was the flat area on the top of the barrel that serves to align the barrel the same way the witness marks do on the M1903.

Jim
 
I googled around, some say the Knox Form is the flat on the reinforce, some (a minority) term it the whole reinforce.

I kind of dropped out in the era of Rigby flats, myself.
 
Okay, so all tapered barrels should have this bulge at the frame end? This makes the M19 not a tapered barrel?
 
The S&W Model 19 does not have a tapered barrel, it is their heavy profile, first seen that I know of on the Heavy Masterpiece K38 of the early 1950s.

However, not all tapered barrels have a distinct enlargement at the receiver.
A Colt Officer's Model Match would be an example of that type.

Maybe if you could let us know just what you have in mind for that "very custom revolver" we could discuss specifics.
 
Well, I said "VERY" but as to what degree, I wouldn't know until I know what could easily be done and what could not. What I would like to achieve is a bkue 7 round 38 Special in a K frame with a 3 inch barrel. From what I've read, it does not sound like a cylinder that can fit inside a K frame has enough space for a 7th chamber even at 38 Special minimal wall thickness. That leaves me with an L frame, such as a 586 Plus.

Several problems arise with this. 3 inch 586's are extremely hard to come by, (besides L-Comp) and as far as I can determine, none are of the Plus variety except for the L-Comp. I don't want a compensated barrel, and also don't like the full barrel lug. What I would like, ideally, at this point is to get a barrel with the profile pictured above in 3 inches, threaded into a 586 Plus frame. I do not know if a K frame barrel can be custom attached to an L frame though, and I'd like the pronounced slope at the receiver as indicated in the topic, which a M19 doesn't have. The picture I posted is a 3.5" M27. The M24 comes in 3" with the tapering cone, but in 44 Special. Although, I wouldn't mind carrying 44 over 38 if I could get 6 rounds of it into an L frame.

Any thoughts then besides "willing to compromise?" Compromise is always an option in pretty much anything, but if the feasibility is there even through having a 3rd party create a barrel from scratch, it would be a great project and carry gun
 
Each frame size S&W has its own barrel shank diameter, they are not directly interchangeable. You could reduce an N frame barrel to fit the L frame but the rod end latch would not line up. Sculpting an L barrel to look like an N would be more than just an expensive gunsmithing job; finding somebody willing to take the time away from regular work to do it at any price would be difficult.

There were a few 686 Mountain Guns with tapered barrel and the Elerius Cone. Six shot, unfortunately. So buy one of those and a 686 Plus, pay a gunsmith to swap barrels and saw off the tapered barrel to 3" on the Plus. Then have it finished in black stainless by Robar.
 
Okay, so all tapered barrels should have this bulge at the frame end? This makes the M19 not a tapered barrel?
Click to expand...

Smith and Wesson made a number of tapered barrels. In some the taper was gentle in others less so. What you see in the pic you posted is not a bulge but just a barrel with a sharper taper rather than a more gradual one. The od of the barrel at that point is the same as the other types (maybe smaller) so is not a bulge.

tipoc
 
There were a few 686 Mountain Guns with tapered barrel and the Elerius Cone. Six shot, unfortunately. So buy one of those and a 686 Plus, pay a gunsmith to swap barrels and saw off the tapered barrel to 3" on the Plus. Then have it finished in black stainless by Robar.
Click to expand...

I guess that's the nearest thing I could do, and a lot of trouble to get the barrel profile I want. Perhaps that is what I'll have to do. It even looks like there's a 686 Mountain Gun Plus, which is something I've never heard of.

Smith and Wesson made a number of tapered barrels. In some the taper was gentle in others less so. What you see in the pic you posted is not a bulge but just a barrel with a sharper taper rather than a more gradual one. The od of the barrel at that point is the same as the other types (maybe smaller) so is not a bulge.
Click to expand...

I know the barrel isn't literally bulged, I just used the word as a shortcut to describe the outer diameter
 
I know the barrel isn't literally bulged, I just used the word as a shortcut to describe the outer diameter
Click to expand...

That's what I thought, but it also means that a revolver smith like Hamilton Bowen and others can machine the profile you want by removing material. You aren't limited by current barrel contours.

tipoc
 
The 686 Mountain gun actually came in a 7shot variety. So tracking down one of those would probably be your best bet. or a track down a separate Mountain Gun barrel (they're out there) and have it attached to a 686+ frame.
It is a 4" though and I would do some very diligent research as far as cutting it goes. I don't know if they were one piece or two piece barrels. If it's a one-piece it should be no problem. Cut it like you would cut any other barrel. Two-piece barrels though, probably can be cut if you absolutely have to but it's gonna be alot more involved than just taking a saw to it.

I would think making a whole new barrel from scratch would probably be the easiest option here.
 
You must log in or register to reply here.
Back
Top