Does anyone have first hand knowledge if these barrel shanks are identical with a high probability of lining up (timing) and headspacing without set back, fitting, etc?

I know pre 64 Win 70's swap pretty easily and what to watch out for. I never had a Classic gun apart or saw a removed barrel.

I hear a lot of tales of them fitting no problem and of them not fitting at all without additional lathe work. Does anyone have first hand knowlefge/experience in this?

You MIGHT get lucky and have the classic barrel line up but I doubt it will.

Well mathematically? You have a 1 in 62.5 chance of the sights coming to top dead center. And after finding one that does that and have the headspace come to zero, that's another matter all together.

I am just curious is all. Someone on another forum said it was a direct swap. I had always heard it was not and was a bit disturbed at all of the Classic barrels that I passed on in the past that may have filled the bill.

Some post 64 classics have 16 tpi and others have 28 tpi.

quote:

Originally posted by airgun1:
I am just curious is all. Someone on another forum said it was a direct swap. I had always heard it was not and was a bit disturbed at all of the Classic barrels that I passed on in the past that may have filled the bill.

Well, a lot of guys look at the drawings and they are the same or close so they figure that you can just swap them back and forth. If you're not concerned about headspace or where the sights end up, then I suppose you could call it a direct swap. The only screw on barrels that I have ever encountered that are simply screw off and screw on to a different gun are the Japanese Weatherby Mark V rifles.

I think most of the manufacturers still thread in lathes or in heavy screw machines with taps Duane. (CNC or other) Which means the threads start wherever they happen to start. When I was working for Weatherby, I was told that the Japanese were doing them in the mill and interpolating them using a point like the receiver face as a Z axis zero and a point on the receiver like a tang screw hole to find X and Y axis. In doing that they made the threads start at exactly the same coordinates every time. Not rocket science. Just a special holding fixture and a breakaway from the traditional way of doing it. The barrels were then threaded, chambered and screwed into a universal block to hold them and witness them during the caliber rolling so that each one was a clone of the next. Not especially hard to do, but when you're tooled up and producing something it can sometimes cost you a years profits to break the system down and change it just because somethings cool or novel. And lets face it. Barrel interchangeability is not really a big requirement in modern firearms. The Japanese probably did it simply because they were starting from scratch and it offered some shortcuts that eliminated some hand fitting costs during manufacture. And, the Japanese started making them right when reliable tape machines were becoming readily available and you guys had blown up all of their old equipment, so why not use the new stuff? LOL

In my experience, pre-64's will almost always index very close unless the receiver has been faced. Pre-64 to Classic will usually headspace OK but never index.
Interestingly, I have switched barrels between pre-64's and Model 54 Winchesters and they indexed as well. I have never had a barrel on any post-64 index correctly when switched to another action although, as I said, headspace was generally OK. Regards, Bill

Now that I'm thinking about it, Remington actually cheated in their final fitting and made 3 different bolt lengths to shortcut final headspacing. They run the reamers in and shoot for dead on. If things don't quite work, (which happens to everyone off and on) they simply reach in the bin and grab an oversize or an undersized bolt. 98% of the time that fixes the hiccup without pulling the barrel and making manual corrections.



REMINGTON HEADSPACE by Rod Henrickson, on Flickr