This topic has recently been covered in depth. Thread (New member with Model 70 questions) is on p.7 of this (Winchester Rifles) forum….

Hi Fairlane-

If we proceed on the premise that Winchester would have made these standard grade stocks with SG style swivels from scratch and not by altering already finished stocks, then there are several ways to tell.  If the factory installed them the same way a home craftsman would, then there may be no way to tell and the origins of the swivels will always be questionable.

The photo below shows the placement of the butt stock swivel on a standard grade and SG stock (these happen to be FWT stocks, but it doesn’t matter).  Note that the center of the swivel is in the same place, such that the holes (one for standard, two for SG) are in different places.  If you remove the rear SG swivel base and there is a covered up wood screw hole, it’s likely that the SG swivels were added later.  If the SG base uses a hole located where the standard swivel hole would be, i.e. center of base is either further forward or back of the standard location, it’s doubly likely that the SG swivels were added later.

The second photo is of the fore end of the two stocks.  Two things to note here.  First is that fore end wood was coved to allow clearance for the detachable swivel.  As you know, these coves vary a good bit in depth and crispness of the edge, but typically run roughly in an arc from about the center of the two swivel attachment screws.  Factory installed SG swivel bases would likely be similarly relieved if installed on a standard stock.  Installing those bases correctly on an already finished stock would involve some refinishing that might be evident.

The second thing to see on the outside (probably less helpful) is that the center of the swivel on a SG stock is further back from the fore end tip than on a standard stock, i.e. the forward hole for the SG swivel base is not in the same location as the single hole for the standard swivel.  However this was done to avoid wood splitting between the front edge of the SG swivel base and the black plastic fore end tip.  I’m not sure where the factory would have chosen to place the front SG swivel base on a standard stock.  Just eyeballing photo 8-17 in Rule’s book, which purports to show a factory-installed SG swivel base on a standard grade fore end, it looks to me like the base was installed so as to maintain the standard distance between front/rear swivel centers, i.e. the two SG screw holes straddle the location of the standard swivel hole (???).

It might be helpful to compare the distance between the center of the swivel and tip of the fore end on your stock with SG swivels to a standard grade rifle with the regular swivel bow.  Does the SG base use the standard hole location for one of the screws or is the base centered over where the standard swivel would be.  If the latter, then as with the butt stock there should probably not be a covered up hole under the SG base.

Finally, the thing that is probably most definitive would involve looking in the barrel channel.  The standard swivel attached via an escutcheon and the barrel channel was routed to accommodate it.  The SG swivel screws attached via two knurled nuts inserted into round holes.  So a rifle with factory installed SG swivels would likely not have the barrel channel routed out for a standard swivel escutcheon.  If done later, this routing would probably have to have been filled with a piece of wood, especially if the standard hole was used for one of the SG swivel nuts.

Of course all this is based on the premise that the factory would have made the stock up special, i.e. before routing/drilling for standard swivels.  That would almost surely have been the case if, as you suggested originally, that a production run of standard grade rifles was done this way.

I hope this helps.  

Lou