Factories change things and some times they screw up or make something "custom" that slips into the mainstream, and sometimes they just have a better idea. Sometimes that "better idea" comes from a bean counter along the way though, so be wary. 16"/21"/23" barrels should have the same spacing, 12" and 14" should have the same spacing,,, BUT BUT BUT, the world is full of butts. FWIW, I added a second dovetail to my early 21 inch tapered 7TCU barrel, it did not change accuracy but I did sleep better at night.
I had a very early 21 inch tapered 30-30 contender with super 14 spacing. WHY/HOW DID THAT HAPPEN?. I have an H&R topper with factory walnut that isn't supposed to exist according to some internet eggspurts. I also have a Rem 788 in 30-30 with a factory walnut stock that a lot of guys will tell you does not exist. My Remington 788 in 30-30 was originally owned by the Michigan Department of Corrections (still has the StatePrisonSouthernMichigan armory tag and number on a brass plate glued to the grip cap area in fact). I doubt the state paid for that very nice walnut upgrade. As it turns out Remington only put walnut on the very early guns despite what some will say.
**** Happens comes to mind sometimes. If you have ever worked in a factory you get how **** happens and things change by date or by the day of the week. Pre 1978 I imagine things walked out of factories occasionally so there are weird things out there "that do not exist" in nature...……. Stay ever vigilant.
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