1903 is a totally different rifle.... different stock, single load vs. magazine fed, different barrel, different trigger (Model 5098)
Basically only the receiver/bolt is the same.
Key features of the 64R Biathlon: (taken from the 2006 Catalog)
ANSCHÜTZ special biathlon barrel, cold-tested
Match trigger:
5103 adjusted to 1500 g & 5104 adjusted to 550 g.
Stock:
The anatomically perfect stock is lacquered and includes an aluminum grooved rail for
hand stop & aluminum grooved rail for harness.The butt plate 4709A is adjustable vertically and in length by 8 mm spacers 4709 P.
The aluminum butt plate 4759 or 4758 can be fitted.
Stock is cut out for the Magazine holder 1927-U23 for 4 magazines(fits models 64 R Biathlon and 1827 ANSCHÜTZ Fortner)
Delivered with:
One 5 shot magazine, screw driver and manual with test target.
The closest rifle today that Anschutz makes is the 64 MP R, although a totally different stock from the 64R Biathlon.
Your not looking for this model to actually use in Biathlon?