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View Full Version : Colt revolver question (more lr less revolver in general)


Doug.38PR
June 30, 2005, 08:16 PM
As some of you may know, I own two Official Police revolvers 1961 and 1944. A while back, I noticed that the force cone was a little wider on my 1961 than on my 1944 and that the rifling started soon after the smooth tapering down. At first I thought "OMGsh, the gun has been fired A LOT and the force cone is worn down" On my 1944 the cone is a lot narrower and the rim is thicker and the rifling starts closer to the begining of the cone.
It was recently suggested that the 1961, if I understand the meaning of what I was told correctly, was purposely done like that not due to overshooting the gun up, but was fitted like that to give the gun a smoother and wider tapering down to increase accuracy of the gun. Whereas on the 1944 version it probably needs to have the cone widened to 1) prevent lead buildup and 2) to prevent the bullet from tumbling at the front of narrow cone so it smoothly slides downt the cone and into the rifling.

I'd like to have a second opinion on this. I am already having it done to a S&W .357 with the same problem. I understand this can increase the accuracy of the gun.

Thank you,
Doug

Handy
June 30, 2005, 11:39 PM
I assume you're having a leading and/or accuracy problem with the '44 gun?

Dfariswheel
July 1, 2005, 12:13 AM
The Colt forcing cone is a good compromise as it comes from the factory.
Factory spec is about a 9 degree cone, and works well with both lead and jacketed bullets.

If a shooter intends to shoot mostly lead bullets, the cone taper can be cut to around a 11 degree taper, and for mostly jacketed bullets, you can use an 18 degree taper.

The reason for the different angles is to ease the entry of the bullet into the bore, which reduces bullet deformation.

One thing about forcing cones.
Taper and depth is not really critical, unless you're building a full-blown Match revolver where you're trying to squeeze the absolute maximum accuracy out.

What IS critical is the outer mouth of the cone.
The outer mouth is THE critical dimension, and if the cone is mis-cut, accuracy is gone.

If the outer mouth is too large, accuracy falls off. Too small and accuracy falls, and the gun will spit bullet material.

The ONLY way the cone can be measured properly is with a special forcing cone plug gauge. It cannot be "eye-balled".

The difference between too small and too big is VERY tiny.

Few people, even gunsmiths really know much about proper forcing cone specs, and even fewer know the mouth diameter is what's important.

In the case of your Official Police with the different cone, it's almost certainly an after-market alteration, which also means it's likely suspect unless whoever did it had the plug gauge and knew how to use it.

In any case, with a non-Match revolver, re-cutting a cone isn't cost effective unless you have a friendly 'smith with the tooling who's willing to give you a price break, or if you just want to experiment with getting the most out of a non-Match Colt revolver.

Doug.38PR
July 1, 2005, 09:50 AM
The gunsmith that spoke to me about it, showed me the tools and the steps he goes through to increase the mouth of the cone (one of them did look kinda like a mini pine cone). he said he has been doing it to his own revolvers and others for years.

Dave Sample
July 1, 2005, 12:15 PM
If you want to know if a revolver has been shot a lot, look for the flame cut on the inside of the top strap right above the barrel.

I re-cut forcing cones all of the time on 1873 type revolvers and it does make a difference in how they shoot. I use an 11 degree cutter and then a facing cutter to make the end of the barrel straight. It stops them from spitting lead out the sides of the cylinder and helps get that bullet out of the chamber and down the barrel right.

James K
July 2, 2005, 10:05 PM
I might also note that a larger cone can make up for a small mis-alignment of the cylinder, where a tight cone will result in spitting lead if the alignment is not perfect.

Some folks will swear that Colts "lock up tight" and are "always in perfect alignment". Even if the alignment is perfect on all chambers from the factory (it isn't), it might not last. It sounds good, and Colt salesmen preached that sermon for years, comparing a "tight" Colt to a "sloppy" S&W. But that "tight" lockup system, once it takes on some wear, can actually force the cylinder out of alignment and make things worse. A larger cone will make up for that.

Jim

Dave Sample
July 3, 2005, 02:24 PM
That is why I install a hammer stop in every 1873 type that I tune up. I drill and tap a hole for a set screw that goes right under the hammer roller and stops the hammer dead at full cock so we don't let the hand try to turn the cylinder while the bolt has it locked up in the notch. It stops that nonsense and makes the tune up last a very long time. It also can be adjusted from time to time ,if need be.