White Lightning Liner failure

[Simon]

I installed a White Lightning LINER and after shooting 10 or 12 shots, the liner fractured just below the first thread.  Of course I don't know when it fractured, but the top portion unscrewed until it was stopped by the pan.  The lower portion  came out easily with a screw extractor.
None of the threads on either part were striped and I could not see any sign of stress in the body.  A 14/32 tap was turned into the hole with finger pressure only and no problems were found.

The liner was installed in a hooked breech and was drilled and tapped into the powder chamber.  There is no ledge on the bottom of the hole.  The hole was tapped 14/32 and counter sunk per the instructions that came with the liner. I can't remember if I lubed the threads before installation. This was the last of four white lightning liners that I have installed and no problems with the others.

Is there any thing else I should do before installing a new liner?

Please do not post about using a plain hole and no liner, or about the quality of the liner, I have no questions about that.

If you can see any thing I did wrong or should do  differently, please tell me.

Thanks      Mel

[P.W.Berkuta]

Mel, from what you say I don't think you did anything wrong -- to me it sounds like you had a defective liner either the inside hole was oversized or the outside thread was cut too deep which reduced the wall thickness of the liner and when screwed in to the barrel a fracture developed and failed after XXX number of shots -- my opinion.

[FlintFan]

This is a tough one.  If it failed at the first thread, the wall thickness of the liner should have been fine.  I think they have a rounded chamber inside, which means the walls will get thicker the closer you get to the outside of the liner.  The outside couple threads should have plenty of thickness under them.  I find it very hard to believe that it could fracture and blow out just by firing.  It might be possible that it fractured on installation.  If it was overtightened, it could have cracked under the countersunk head when it was being wrenched down.  It can be tricky judging torque when installing a white lightning liner.  You have to clamp on with a vise grip and turn it in.  It can be very easy to over tighten.  Just an idea. 

[Bill of the 45th]

Please contact Jim Chambers by email, or better yet by phone.  He will want to know about this, and I am sure will take pains to resolve the problem.  There is a lot of expertise on this site, but this is his product, and he could best advise you.  I'm sure he will want to see what happened to the liner.

Bill

[dbraw]

If a liner is tightened too much, it can break. I had one do this a while back. Talked to Jim Chambers in Lexington and he said it had happened to him also.

[Dr. Tim-Boone]

That is an interesting problem. Seems that if one over tightened the liner it would have broken at the connector between the liner and its tightening stub.......

[Simon]

That is an interesting problem. Seems that if one over tightened the liner it would have broken at the connector between the liner and its tightening stub.......

My thought was that the liner bottomed  out on a bad thread and I over tightened and fractured it, however there is nothing in the hole now, but there could have been.  I will finger tighten the new one and not use vice grips until the very end and just enough to make it snug.

Thanks for the replies.       Mel

[Dave Faletti]

If you can screw it in til the head contacts the chamfer with your fingers you must have cut full threads the whole depth.  How are you planning on keeping fouling from working its way up the threads?  There won't be a seal on bore side of the threads.

[little joe]

I broke one in the same spot. My fault, tightened too tight. Be careful.

[volatpluvia]

For the three that I installed, I bought the kit from Chambers.  I had to use a pliers to turn the liners into the holes after getting them started.  None of them ever backed out.  I am trying to visualize how they would do that.  Well, I am glad yours did not blow out.
volatpluvia

[A.Merrill]

    Could it be a problem with the tap that was used to cut the threads in the barrel? Even if it was 1/4 32 tap, if the threads are deeper than the threads on the liner it would allow the liner to expand and crack under the pressure of the charge going off in the barrel.
    Or the threads on the liner were not tall enough to fill the threads made by the tap. I don't know, just thinking after a 12 pack and 2 shots
           HAPPY NEW YEAR     AL   

[JCKelly]

Out of curiosity, do any of you guys know if these White Lightning liners can be picked up by a magnet?
Which would mean they are 416 stainless?

[Dphariss]

Out of curiosity, do any of you guys know if these White Lightning liners can be picked up by a magnet?
Which would mean they are 416 stainless?

I believe they are 303 or 304.

Dan

[Randall Steffy]

It seems to me that a countersink which is not concentric with the tapped hole would introduce the sort of stress on the liner which could cause just the type of failure described by the original poster.

[Long John]

Rather than using vice grips to screw the unit it I just take a hack saw and cut a slot for a screw driver.  Secondly, I tap all the way into the barrel and use a little Lock-Tite "blue" #242 thread sealant.  I have never had any evidence of blow by or leakage.  I don't see the need for trying to get a sealing thread engagement, especially since it is doubtful unless you are using a tapered thread.  We are not!  I question whether an incomplete straight thread is a valid subsitute for a tapered thread.

Best Regards,

JMC

[Jim Chambers]

My best guess without knowing exactly how the liner was installed would be overtightening when installing the liner.  I have seen this happen one other time.  Fortunately, that time the liner broke during installation and before the gun was ever fired.  A new liner was installed using less force to screw it in, and all was fine.
The alloy we use for these liners is 303 stainless as was suggested above.

[B Shipman]

I'm convinced this is  a matter of  tearing the liner on installation. Gas cutting with poor installation is about the only other thing that can go wrong.  Though i've not had the problem, I take this as a learning experience to not go crazy on mine. So thanks for bringing it up.

[Simon]

My best guess without knowing exactly how the liner was installed would be overtightening when installing the liner.  I have seen this happen one other time.  Fortunately, that time the liner broke during installation and before the gun was ever fired.  A new liner was installed using less force to screw it in, and all was fine.
The alloy we use for these liners is 303 stainless as was suggested above.

I have decided, from the answers, that I probably over tightened the liner by trying to screw it to deep into the counter sink.

I have never questioned the quality of the liner as I stated in the opening post.  My question was Solly about what I did.   

Thanks to everyone for their comments.       Mel