Bill Hockett said
Does anyone have some idea when the little set screw was added to the sporting front sight (later known as model 21 series)?  In my collection I have an 1873 rifle that was made in 1876 that has the sight with no screw.  I also have an 1876 rifle that was made in 1882 that does have the screw on the sight.  It does not have a patent date. Both these rifles appear to have original sights.   

In my collection I also have a 21 series sight (I think it is a 21K) that has a tinned tip and “Pat. Nov. 4, 1902” marking.  According to the Madis sight book the tinned tip and patent mark were added as of 1/15/17

None of the sight books seem to be much help on this.   I suspect that like anything Winchester there was no hard date when they stopped using the sporting front sights without the screws.  The bins that held sporting front sights may have had a mixture of those with and without the screw for a while.  

Thoughts?  

Hi Bill,

According to the Winchester factory drawings the tinned tip and patent date for the 21K was added 1/16/17 (not 15). 

As Bob mentioned, the screw was added to the 21 sight in 1895 and according to the Winchester sight drawings for the 21 sight it was omitted from most versions on 2/9/26 per Change in Manufacturing notice number 11182.

Hope that helps,

Regards,