what caused forcing cone to split???

[dickwholliday]

i saw a 686 with a split in the barrel at the forcing cone at the indoor range yesterday....when they finally got it apart i looked at the brass and it looked OK...no eviidence of cratering or heavy loads....the owner of the gun was not there to talk to but he was shooting reloads in 38 brass.....any ideas?????? D I C K

[Round_Gun_Shooter]

Very possibly a timing problem but without seeing it that has to be a guess.

Regards,

[dajarrel]

I was reading this week in Mr. Sweeney's new book on S&W handguns (well it's new to me) that a gun that has a steady diet of lead bullets and then has jacketed shot behind them can cause a forcing cone to split/crack.

I have in the past shot a lot of lead bullets in my M19 resulting in alot of lead in the forcing cone area. I would then shoot a couple of .357 mag loads with JHP bullets in them to "clean" it out.

I'll be very leary of that practice in the future. I've been lucky.

Maybe your friend wasn't.

FWIW

dj

[Bubber]

I have seen, Broken, forcing cones on the K frames but never the L frame Smiths. On the K frames the Forcing cone has a portion taken away at the bottom to make room for the cylinder/yoke to close. The problem I had was shooting a light bullet (122 grain) at a 127 power factor (about 1050fps). Not high pressures but 38 specials aren't pushed that fast generally. I would look at what weight bullet and velocity are being shot. The L frame's forcing cone does not require it to be modified to accomidate the cylinder/yoke fit. good luck rdd

[EricW]

I was reading this week in Mr. Sweeney's new book on S&W handguns (well it's new to me) that a gun that has a steady diet of lead bullets and then has jacketed shot behind them can cause a forcing cone to split/crack.

Which is exactly what I did to my Dad's Colt.

[1911user]

I was not aware of this danger with K-frame smith's. Thanks for the heads up. (just bought a used model 13 S&W)

Does it affect all DA revolver (like Ruger)?

How safe is it to shoot jacketed ammo after cleaning the lead out of the barrel (and forcing cone)? Are there special steps for cleaning the forcing cone?

I'm assuming that a steady diet of lead or a steady diet of jacketed is OK, but jacketed after lead requires a good cleaning step.

I'm beginning to doubt the idea that .357 mag pistols are tough beasts and that's not comforting.

[revchuck]

1911user - Don't take this out of context. This is the first time most of us have heard of an L frame cracking there, which means it's an unusual occurance. K frames, like your (and my) M13 sometimes have problems shooting full power 125 grain .357s due to the impact of the bullet on the forcing cone. The problem is specific to that load; you can shoot full power 158s just about forever through the same gun.

The shooting-jacketed-after-lead thing is a problem when you have so much lead in the barrel and forcing cone that you can barely, if at all, see the lands. It's a dumb idea in either a revolver or a bottomfeeder. The way to avoid it is to work up loads that don't leave that much lead in the barrel. Leading is NOT inevitable.

[dickwholliday]

Sorry guys....gun was k FRAME 66....i guess i was so busy looking at fired cases ect that i didn't take a good look at the model #........thanks for the replys....thanks...D I C K

[1911user]

1911user - Don't take this out of context.  This is the first time most of us have heard of an L frame cracking there, which means it's an unusual occurance.  K frames, like your (and my) M13 sometimes have problems shooting full power 125 grain .357s due to the impact of the bullet on the forcing cone.  The problem is specific to that load; you can shoot full power 158s just about forever through the same gun.

The shooting-jacketed-after-lead thing is a problem when you have so much lead in the barrel and forcing cone that you can barely, if at all, see the lands.  It's a dumb idea in either a revolver or a bottomfeeder.  The way to avoid it is to work up loads that don't leave that much lead in the barrel.  Leading is NOT inevitable.

That makes alot more sense, thanks for the sanity check. I've owned a M19 before, but wasn't aware that the forcing cone was weakened at the bottom or that magnum 125gr jacketed loads were so hard on the revolver. I normally use harder cast lead bullets at 38+P levels so leading has never been a problem. I'll pass on the steady diet of magnum-level 158 grain loads; those aren't much fun to shoot

[Allgoodhits]

I was not aware of this danger with K-frame smith's.  Thanks for the heads up.  (just bought a used model 13 S&W)

Does it affect all DA revolver (like Ruger)? 

How safe is it to shoot jacketed ammo after cleaning the lead out of the barrel (and forcing cone)?  Are there special steps for cleaning the forcing cone? 

I'm assuming that a steady diet of lead or a steady diet of jacketed is OK, but jacketed after lead requires a good cleaning step. 

I'm beginning to doubt the idea that .357 mag pistols are tough beasts and that's not comforting.

Cleaning the forcing cone can be done easily with a caliber specific LEWIS LEAD REMOVAL kit.

The kit has a rod, two jags and a set of screens for cleaning. One jag is cone shaped to clean the forcing cone with the screen and the other jag is designed to pulled through the barrel from the chamber to the muzzle.

MJ

[Wap wap]

Had a K frame do the same forcing cone split from lead then jacketed- Learned the hard way although S&W replaced it. Now I always use an 11 degree forcing cone reamer and facing tool on a new gun.