The 640 is another version of the 648 in 8x57Is ,that i have . They are FN 98 receivers and they are very fine rifles . They can be difficult to get,but they are fine to custom make a rilfe out of. The most expensive i have seen cost nearly 15000 dollar and it had all trix and trades of the gunsmith in it.

In short. they are superb rifles and the 9,3x62 is a superb rifle and after the information i got is that they wasnt made in so many numbers, so if you have the chance to get one ,buy it!! And use it for all hunting and shooting .