Several years ago I owned an FN Mauser sporter in .250-3000,
it was serial numbered on the reciever, barrel, and bolt.
If I remember correctly, it had a stepped barrel, but I might
be wrong. I sold it about 6 years ago when money was tight.
From a distance it could easily been mistaken for a Winchester
70 SG. I currently have a pair of Mauser M1936s, one of them
may become a 250 Sav when I get around to it. I believe
Brownells sells barrels for Mauser 93,95, and 96 in mild
cartridges such as 257Sav,257R,300Sav, and 35Rem.