oldracer
11-26-2012, 11:53 PM
In my earlier post further down the page I mentioned that the barrel on my 1871 receiver/Badger barrel 45-70 had come loose and mentioned what Doug Knoell, a local national level BPCR competitor (retired, with cancer) and master gunsmith suggested as the fix. I asked for other opinions and got several ranging from a re-machine (not feasible due to costs), using a copper crush washer (both commercial and home made) and a wrap (or two) of copper wire to act as a washer. Doug suggested making a washer of J-B weld after cleaning and measuring everything very well. So here is what I did.
First, was a very good cleaning of the barrel and receiver threads and the shoulders where the barrel sets against.
Second, I coated the barrel thread area with machinists layout blue and let dry.
Third, I screwed in the barrel and snugged it down, but not super tight and then carefully backed it out. I noted that the vertical edges of nearly all the threads and the inner and outer shoulders had blue transfer. About 40 to 45% of the thread flats also had blue transfer so those both told me that threads were well made and confirmed the tight feel of the threaded joint when putting in the barrel.
Fourth, I took the barrel to the best source for shim material and tools in the San Diego area and looked to fine material 0.0046 inches in thickness and this would give me a 20 degree pull up on the barrel. 12 T.P.I = 0.08333/turn, 20 degrees = 1/18 of a revolution, 20 degrees = 0.0046 axial movement or take up. The problem turned out to be the O.D. of the required shim which was less than 1/8 total. So after looking at a couple of gasket cutter sets which were expensive and not being able to guarantee a good cut gasket, I decided to quit this idea.
Fifth, I bought some copper wire, 0.005 inches in diameter and tried that. I wrapped one complete turn and then tried two turns and in both cases the take up was not even and would usually go past the index marks, so I quit that idea.
Sixth, I cleaned everything and tried the J-B weld idea and did as Doug suggested, using some mold release on the receiver and putting a small bead where the outside edge of the barrel threads ended. I already had the receiver mounted in the padded vice with the rear tang vertical as before and screwed in the barrel, stopping at about 20 degrees before take up. I noted that the J-B was pretty much all inside the receiver and not visible. I let it setup for an hour and then tightened the barrel until the top flat was exactly level as the tang in back had not moved. The last 5 degrees were a bugger and the barrel was let to sit over the next 3 days.
Today I went and tried the fix and accuracy is back to what it was. There was no J-B weld leak out and no indication of the barrel coming loose and I pulled the fore stock off and tried to loosen the barrel and it would not budge. So it appears the fix is going to work and I'll have to see if this lasts as long as the last time the barrel was tightened, about 12 to 14 years ago!
As for issues of pressure, there are none as I can see as all the pressure is inside the barrel and the rolling block locks things up just as before. There might be a very slight expand/contract of the barrel due to the black powder ignition and temp changes but I think that steel in the old Badger barrel does not move much? Anyways, if things change I will immediately make a post and note what happens. Whew!
First, was a very good cleaning of the barrel and receiver threads and the shoulders where the barrel sets against.
Second, I coated the barrel thread area with machinists layout blue and let dry.
Third, I screwed in the barrel and snugged it down, but not super tight and then carefully backed it out. I noted that the vertical edges of nearly all the threads and the inner and outer shoulders had blue transfer. About 40 to 45% of the thread flats also had blue transfer so those both told me that threads were well made and confirmed the tight feel of the threaded joint when putting in the barrel.
Fourth, I took the barrel to the best source for shim material and tools in the San Diego area and looked to fine material 0.0046 inches in thickness and this would give me a 20 degree pull up on the barrel. 12 T.P.I = 0.08333/turn, 20 degrees = 1/18 of a revolution, 20 degrees = 0.0046 axial movement or take up. The problem turned out to be the O.D. of the required shim which was less than 1/8 total. So after looking at a couple of gasket cutter sets which were expensive and not being able to guarantee a good cut gasket, I decided to quit this idea.
Fifth, I bought some copper wire, 0.005 inches in diameter and tried that. I wrapped one complete turn and then tried two turns and in both cases the take up was not even and would usually go past the index marks, so I quit that idea.
Sixth, I cleaned everything and tried the J-B weld idea and did as Doug suggested, using some mold release on the receiver and putting a small bead where the outside edge of the barrel threads ended. I already had the receiver mounted in the padded vice with the rear tang vertical as before and screwed in the barrel, stopping at about 20 degrees before take up. I noted that the J-B was pretty much all inside the receiver and not visible. I let it setup for an hour and then tightened the barrel until the top flat was exactly level as the tang in back had not moved. The last 5 degrees were a bugger and the barrel was let to sit over the next 3 days.
Today I went and tried the fix and accuracy is back to what it was. There was no J-B weld leak out and no indication of the barrel coming loose and I pulled the fore stock off and tried to loosen the barrel and it would not budge. So it appears the fix is going to work and I'll have to see if this lasts as long as the last time the barrel was tightened, about 12 to 14 years ago!
As for issues of pressure, there are none as I can see as all the pressure is inside the barrel and the rolling block locks things up just as before. There might be a very slight expand/contract of the barrel due to the black powder ignition and temp changes but I think that steel in the old Badger barrel does not move much? Anyways, if things change I will immediately make a post and note what happens. Whew!