Serial number 842,000 would be 1953'ish.
Serial number A842000 would be early 1970's.

Do you see why the serial number designation on that might have just a bit to do with the thread since the change in threading happened at 1960 with serial number 1,000,000? All Axxxxxx serial numbered rifles would be V thread.


Now, as to the serial number 767,000 that is in 22-250.. that rifle would date to 1955'ish, and would have originally had square threads unless it also has a letter prefix. And there's no reason a 22-250 can't fit into any pre-1960 receiver without any modifications to the internals. The COAL is less than the parent 250-3000 case. The pressures are significantly higher than a 250 Savage or 300 Savage cartridge, but the cartridge would fit.

If 767,000 does have V threads... then something else weird happened to it.

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