Smith & Wesson produced some 20 round boxes of .44 magnum ammo. They were blue and white boxes. When were they initially introduced? Some boxes have a serial number or code on the box end and some do not. Did one variation precede the other, and if so, which was the earliest.

Thanks for any help with my query.

Gary

The S&W brand ammo was made from 1970-1981. The .44Mag JHP load was one of the first loads introduced in the S&W line.