How to fix underhammer breechplug to receiver fit

[bhuch5]

I am in the process of building an underhammer from parts and pieces using Hopkins /Allen lockwork from Deer Cr Products.The receiver is made from 1 1/4 brass shaft which I bent in my shop. A machinest milled slot for hammer and trigger for me.My problem came about when I drilled the receiver for the 5/8 breech plug. My drill press had too much slop and the breech plug hole is somewhat oval shaped.In other words my barrel has too much up/down play when installed.I tried JB weld to tighten the gap and this held for awhile but is breaking out now. I have considered having machinest rebore receiver to larger size and soldering in a bronze bushing to hold plug. Do not want to have a new breech plug made and am looking for repair options. Any ideas? Thanks loads for your help. Bruce H

 

I think you are on the right track. I would pull the plug, and take it and the receiver to the machine shop. Have them overbore it, fit a sleeve or plug. Have it silver soldered, and rebore to fit properly.

Bill

 

[Birddog6]

This thread just screams future Darwin Award. :shake:
JBWeld in a breechplug ! :shocked2: :youcrazy:

Take it to someone that KNOWS how to breech a BP rifle. :slap:

Keith Lisle

 

[Capt. Fred]

Kieth, I don't think he means that he used JB Weld to hold the breech plug into the barrel. (God I hope that is not what he meant!!) I think he means where the outer end of the breech plug goes into the reciever.

Some pics would help.

 

[bhuch5]

Thanks for the vote of confidence Keith.Breechplug is fitted correctly WITHOUT JB weld into end of barrel. Looseness is where Underhammer breechplug slips into receiver. Held in place by 3 screws similar to Hopkins/Allen method. Hole in receiver is ovalled slightly making for a loose fit. Hope this clears things up. Bruce H

 

[sbhg]

Strip the receiver and add a bead of braze on the inside top and bottom and have that machine shop bore it to the correct size. http://jwharris.com/~/media/Files/PDF/Requested Resources/FillerMetalSelectionChart.ashx
http://jwharris.com/en/Products/Alloys/Brazing.aspx

 

[mazo kid]

I feel your pain...but a drill press and drill bit do not make for a snug fit. I think you have received good recommendations as to how to do the fix. I would have a sleeve welded or pinned over the round tang and then have your machinist MILL the receiver to fit snuggly. My 2 cents worth.

 

[Birddog6]

Thanks for the vote of confidence Keith.Breechplug is fitted correctly WITHOUT JB weld into end of barrel. Looseness is where Underhammer breechplug slips into receiver. Held in place by 3 screws similar to Hopkins/Allen method. Hole in receiver is ovalled slightly making for a loose fit. Hope this clears things up. Bruce H

That sounds Much better.... Ya about gave me a coronary ! :shocked2:

You said Breechplug Hole, that is where the breechplug threads into the Breech of the Barrel.
:hmm: You didn't say the Receiver hole. :idunno:

Sorry for the misunderstanding.

Keith Lisle

 

[Twice boom]

Have your machinest bore a larger hole and have him thread it . Make a plug with male threads to thread in to the larger hole. Start over from there.
Just a thought.
Twice.

 

[bhuch5]

I fixed it today-lots easier than I had thought.Since receiver portion was brass I chucked a 1/2" diameter grindstone into drillpress(after replacing bad bearings in press).I bought a bronze bushing sleeve 5/8 id x 3/4 od by 1''long.My breechplug fit very snugly into bushing.Scribed around bushing and proceeded to carefully grind breech plug hole in receiver to snugly fit the bushing.(about 45 min) Soldered the bushing into place and filed face flush. Made for a tight neat plug fit for someone without a mill.(also known as fixing yer screwups) Very pleased with the outcome.Thanks all for your suggestions. Bruce H

 

[Capt. Fred]

Sounds perfect. Nice going.