Kai Benedict
.50 caliber
Anyone have success in repairing threads in the drum. Probably overdose taps and nipple?
We need a little more information.Anyone have success in repairing threads in the drum. Probably overdose taps and nipple?
Where in this thread does someone say T/C used a drum?When did T/C use a drum
Where in this thread does someone say T/C used a drum?
Then It was realized that the helicoil problem was in the IBS for a T/C and the helicoil was installed in the snail.Well the Deerstalker/Trade rifle is pretty much a swap.
But the down grade from 54 to 50 would get me PO'd too!!
Gather your best attitude come Monday when ya call,, they'll fix the mess by sending a return label,, but it's gonna take another bunch of weeks!!
I got caught in a Lyman recall when they had that nipple thread/helicoil fix mess with their IBS barrels.
By the time I got the barrel back,, I lost a full season of shooting with it. Thankfully it wasn't my only gun.
Once upon a time, Green Mountain used some incorrect taps to thread the nipple holes in the breech plugs installed in the barrels made to fit the Thompson Centers.
To fix this error, they redrilled the hole and installed a Heli-Coil screw thread insert.
There was absolutely nothing wrong with this however many buyers were upset about getting "reworked" barrels when they thought they were getting brand new barrels. (They were brand new barrels and breech plugs but that didn't matter to the buyers).
To make everyone happy, GM tossed the "reworked" breech plugs and machined new ones.
I mention this because although it is very unlikely that Green Mountain would have any of these "reworked" breech plugs now, they might so you could try contacting them.
Even if they don't have any of the scrapped breech plugs, the idea of using a Heli-Coil® to fix your problem still is worth considering.
On the web, I just found a 1/4-28 thread Heli-Coil® for $0.80. The special tap would probably cost less than $10 so, for about $11 + postage you could have the repair in your hand.
If you do go with the Heli-Coil® method, several things need to be mentioned.
The cross drilled flame channel that connects the nipple with the bore will intersect the Heli-Coil® at the bottom. The length of the insert will be 1/4" long.
Some method must be used to keep that flame path open. If the breech plug has a "clean out hole", you can use it to drill thru the installed insert. That was the original purpose of the "clean out hole" so it can be used again to do the same job.
One of the problems with this type of screw thread insert is they tend to unscrew when the male screw/nipple is removed.
Using a very small amount of a thread locking fluid to bond the insert in place can keep this from happening.
The new Heli-Coil® will be almost as large as the body of the nipple. (see drawing below)
This won't really hurt anything but hot gasses can pass up thru the threads if they are not sealed.
This is a good reason for using some epoxy to bond the insert to the breech plug rather than thread locking compound (which is very thin).
The drawing was made to show folks the differences between using a Heli-Coil® to install a spark plug and using one for a muzzleloaders nipple.
It shows how little of the shoulder on the nipple will contact the breech block to seal it, compared with a spark plug which has a large sealing surface and a spark plug gasket.
As for strength, the pull out or "blow out" strength of the Heli-Coil® is far superior to just a machined thread.
Oh, your right, my bad,, the Green Mountain recall :redface:
While helicoils are used in many applications to repair stripped out threads, I would not recommend a helicoil repair to repair damaged threads in a drum. The coil can go too deep in the nipple seat and block the flash channel and the coil is very hard and may fracture when the gun is fired.
Not too long ago one of the muzzleloader manufacturers used helicoils to repair some damaged threads. As I recall, all the effected guns were recalled. I wish I remembered the details.
Search this Forum using the keyword helicoil. Lyman and the IBS replacement barrels used helicoils. Yes, there was a recall. Whoops, it was T/C.
Lets wait for necchi to respond.
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