Another K Frame Question

[jimmyj]

Hi:
Viewing "Bananaman" post, an obvious question arose:
After an "K" Frame forcing cone "Cracks" is the weapon un-safe to be fired?
If the weapon is now un-safe, what can be done to return the weapon to be shootable?

 

[Alk8944]

If you continue to shoot a revolver with a cracked barrel shank this will damage the frame, even to the point of cracking the lunette. The shank crack allows the barrel shank to expand at the rear as the barrel has lost the majority of it's hoop strength. The expansion effectively rivets the barrel in the frame and can cause it to be impossible to remove the barrel without destroying the frame.

If you are fortunate enough to notice the crack before it has propagated into the barrel threads stop, (unless you don't believe what I have told you and want to discover for your self what happens) and start looking for a replacement barrel.

How do you make it safe again? Should be obvious, replace the barrel.

 

[kbm6893]

So let's say a model 66 barrel is cracked. Can S&W use a model 64 barrel to replace it? I know the K frame .357's are gone, but can a .38 K frame barrel replace it?

 

[john traveler]

S&W would not do such a repair to an M66 using an M64 barrel, but you might find a gunsmith that would. It requires shortening the barrel shank, setting the b-c gap, and re-cutting a new forcing cone. Shortening and fitting the extractor rod and center pin too. It would also require a higher front sight to shoot properly.

 

[dfariswheel]

Another danger of a cracked barrel is that the exposed portion of the barrel around the forcing cone can break off and become a significant piece of shrapnel.
A local indoor shooting range once had a piece of barrel from a cheap revolver almost penetrate the divider between lanes.

If you have a cracked revolver barrel it's no longer safe to shoot in any circumstances or with any ammunition no matter how lightly loaded.

Options are:

Set the barrel back a couple of threads and re-cut the forcing cone.
This may occasionally work, but usually the cracks spread farther forward than it looks and the cracks will simply continue to spread.

Find a replacement barrel of the same model type.
As example if you have a model 66 you could use a model 19 barrel and have it plated to match the stainless 66.
There are other S&W model barrels that could be fitted.

A more expensive repair is to convert the barrel to a shroud.
This is done by boring out the barrel, removing the forcing cone and threaded portion entirely.
The barrel is then bored out to fit a larger than normal barrel liner.
The LINER not the barrel is threaded.
The liner is fitted to the frame and barrel/cylinder gap is set.
The original barrel is then slipped over and bonded to the liner.

Conceivably, you could use the same system the newer two piece S&W barrels use, in which the heavy liner has a flange at the muzzle that holds the outer shroud on.