Barrel Replacement with Factory Barrel - Headspace?

[40-year-AZ-hunter]

Looking for knowledgeable opinions on a project.  I have a pre-64 M70 Featherweight .243 with throat erosion.  I'd like to replace the barrel with another factory barrel.  I see them from time to time on ebay.  Might be .308 or .243.  The question is - if I unscrew the old barrel and screw in another factory barrel so the extractor lines up and the sights are on the top, how likely am I to have acceptable headspace?

I know that if a go gauge does not go, it could be fixed with a reamer, but if a no-go gauge goes it would seem to be a hassle to make the rifle "original".  So I guess the real question is how likely is it to "fit" without modification?

Thanks

[Delw]

not likely.  a non sighted barrel would be far easier then have the holes drilled. you will probably have to still run a finish reamer in there for the gages or worse case skin the barrel face.

The Remington take offs and barrel replacement was always easier cause you just surface ground the barrel lug for fit or find one a tad bigger

[40-year-AZ-hunter]

All the factory barrels have a slot for the rear sight, not holes like Remington.  Also the barrels are slotted at the receiver for the extractor on a controlled round feed action like the pre-64s.  Then there is the "writing" on the barrel that needs to be in the correct position on  the left side.

Hence the question about how likely is headspace to be correct by just screwing the barrel in to the original factory rotation when it is going into a different action than it came from the factory in.

Thanks.

[recurveman]

Does your current barrel shoot good?    Who said you should replace your barrel?  My .243 has throat erosion.   The gun probably has 500-600 shots down the tube and I'll probably never shoot the barrel out.  If the gun shoots fine I would keep shooting it.   If you are worried about iron sights I'm guessing that accuracy isn't your first objective anyways so keep the current barrel.    Even a barrel that is shot out will shot good enough for hunting in most cases.    

[Hoofnit]

I've replaced hundreds of rifle barrels over the years. . . exactly once I had one time up an be correct in headspace 😎 that being said its not much of a job for a qualified smith to do.

 

[40-year-AZ-hunter]

Thank you for the input guys.  I figured it would not be just a screw-in deal.  The rifle still shoots OK, it's just that I thought I might be able to "restore" it to it's former self - sort of like repainting a classic car that still runs good but the paint has faded.

[Bill V]

I have done 3 ea pre 64 model 70 barrel swaps and I am batting 1000. Perfect each time. Jim Kobe did a couple and he told me that 95% success.  It has worked for me

 

Bill

[40-year-AZ-hunter]

On 2/5/2021 at 10:51 PM, Bill V said:

I have done 3 ea pre 64 model 70 barrel swaps and I am batting 1000. Perfect each time. Jim Kobe did a couple and he told me that 95% success.  It has worked for me

 

Bill

WOW, that is encouraging.  Perhaps I'll buy a used barrel on eBay and take a chance on it.  I assume you mean it worked fine by just screwing it in and lining up the extractor slot?  Thanks for your input!

[Bill V]

Correct. Screwed in and headspaced correctly. Pre64win.com did my last one. $175 plus return shipping. His name is Justin and he has used barrels in 243 on his web site.

[40-year-AZ-hunter]

Thanks again!  I'll check his website.