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S & W 29-2 Barrel Swap
4/20/2010 1:04:04 AM
My second handgun ever (1982) was a 6" 29-2 (Dirty Harry syndrome, I guess!). Lost it to an ex-wife divorce in the mid- '90's. Fortune finds me another 29-2 6" about two years ago. Then last year I found a 6-1/2" 29-2 at a gun show (and I had the money! Go figure!). I always wanted a 4" 29-2, so I shopped around and found a 4" 29-2 barrel that I have since purchased. My questions is; now that I have the barrel (in transit) and the donor gun (relax guys, it's the 6"!!! 
), are there any quirks to the barrel swap, or is it a pretty straightforward bit of gunsmithing?
I always wondered how they get the topstraps to line up while maintaining the ideal barrel/ cylinder gap? Conical washers?
), are there any quirks to the barrel swap, or is it a pretty straightforward bit of gunsmithing?
I always wondered how they get the topstraps to line up while maintaining the ideal barrel/ cylinder gap? Conical washers?
4/20/2010 12:04:46 PM
Well this is pretty straight and to the point. If not using a factory fresh never installed barrel. This what may occur, after removing the barrel and preparing for the swap. The used barrel to be installed with the proper receiver wrench, if your barrel lines up TDC (top dead center) - you still have to measure cylinder gap .003 to .009 MAX! If you are fortunate enough to to land in these specs you are good to go! If you can not get the cylinder to close or get a min feeler gauge between the forcing cone and the cylinder you are still in good shape and simply use a forcing cone cutter to remove enough metal til you fall into those specs., and recut your f.cone taper to spec. If you go beyond the max of .009 than it is highly recommended that the shoulder on the barrel be relieved back on a lathe as necessary.
Ron
http://americanarmsengineering.us
Ron
http://americanarmsengineering.us
4/26/2010 1:02:23 AM
Dang, that was a helluva reply! Thanks much!
According to the seller he thinks it has never been installed before.
I just have to find a gunsmith here in Phoenix that is comfortable/ competent in doing the work on S & W's. Used to be easy- finding a revolver smith that specialized in Smiths or Colts. Now it seems to be a crapshoot; after all, the world seems to only buy and shoot plastic semis anymore.
5/7/2010 12:45:06 AM
On a brand new barrel, the shank is left long for fitting. The barrel is screwed into the frame to the proper torque and it should line up at TDC. If it doesn't, the barrel will have to be set up in a lathe and the shoulder set back a few thousands. As an example, if the bbl shank is threaded 28 tpi, there will be about .036" of linear movement for every full rotation....so if the bbl was torqued correctly and lined up at 10:30 instead of 12, you'd need to take about .003" .0045" off the shoulder.
After the bbl is lined up and torqued correctly, the barrel to cylinder gap is checked. If the cylinder won't close, a special tool is inserted though the bore and a 90 degree facing cutter is mounted on the end. A few rotations of the tool are made, the cutter is removed, and everything is cleaned up so another test fit can be done. The process is repeated until the gap is properly set. At this point, a forcing cone reamer(various angles are available) is installed in place of the 90 degree cutter and a similar process is used until the appropriate gage shows the size to be correct.
All of this is done after all endshake is removed from the cylinder and yoke. Also, any timing or lockup issues need to be addressed....and it would probably be wise to check bore to cylinder alignment after installing the bbl.
Edit: bad math
After the bbl is lined up and torqued correctly, the barrel to cylinder gap is checked. If the cylinder won't close, a special tool is inserted though the bore and a 90 degree facing cutter is mounted on the end. A few rotations of the tool are made, the cutter is removed, and everything is cleaned up so another test fit can be done. The process is repeated until the gap is properly set. At this point, a forcing cone reamer(various angles are available) is installed in place of the 90 degree cutter and a similar process is used until the appropriate gage shows the size to be correct.
All of this is done after all endshake is removed from the cylinder and yoke. Also, any timing or lockup issues need to be addressed....and it would probably be wise to check bore to cylinder alignment after installing the bbl.
Edit: bad math
