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Hi all , hopefully someone here can help me , I have a pre 64 model 70 , 1955 year model to be exact ! It’s a .30/06 featherweight , I’m installing a new Lilja featherweight countour barrel , and new McMillan edge stock , the stock is cut for factory featherweight contour but have not received it yet , I was wanting to go ahead and get barrel chambered and installed but my gunsmith does not know the factory featherweight shank length and I do not have take off barrel to measure , does anybody have the proper shank length for the featherweight , and the proper thread length ? Thank you so much !
The threads on all Pre 64 model 70’s are same for all models and calibers.
The dimensions are: tenon length – .730″
Major diameter – 1.000″ +.000″/-.009″
Max minor diameter – .9233″
Pitch diameter – .9594″ +.000″/-.0037″
Threads are 1″ – 16 TPI
Included angle of cone is 96 degrees.
Steve
Thanks for the info Steve , so the threads are actually .730” in length , how long is the non threaded part of the shank on a featherweight? I guess I need the measurement from the very front of The action to the beginning of taper ? Thank you
I make the non threaded part of tenon whatever the action will dictates. I call this a register. The figure I gave you of .730″ is from the mating face of action/barrel to end of chamber. The actual barrel print does not show a register, but obviously, there needs to be some type of thread relief since threads cannot go all the way to mating surface of barrel. I would think your gunsmith would take that into account, this is common practice. I did measure a 270 featherweight barrel I had and it has an unthreaded register that measures .993″ dia x .100″ long.
Now if I understand correctly, you have a 2nd question, which is what is the straight length of barrel projecting from action face forward to where the barrel starts its taper to the muzzle. From action face forward, the barrel measures 1.140″ dia x .190″ long. At a point .500″ from action face, the barrel measures .975″ diameter. The area between the forward edge of the 1.140 x .190″ shoulder and the .975″ diameter is joined by a .500″ radius fillet.
Steve
Hey Steve , thank you so much for
your detailed answers , that is the exact information I have searched the internet high and low for ! Thank you again this will solve all my issues !
Hey Steve would you or anybody here by chance have a diagram or a drawing maybe with this shank and tenon info on it as well as the correct angle and width of the extractor cut ? Thank you !
Sorry, no diagrams. I can tell you that there is a schematic in the Frank De Hass book, “Bolt Action Rifles”. It is pretty basic. As far as angle, I measured a a barrel and the extractor cut is at an included angle of 30 degrees to face of chamber. Factory barrels used a concave cutter to provide a .450″ convex radius on the face of cut. I believe Brownells sells the correct cutter. The extractor cut width is .420″. The Brownells tech line might be a good source for a diagram also.
Steve
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