I have recently acquired a rifle that was disassembled and covered in grease.  I am fairly new to Mausers and was told it was a K98.  I thoroughly cleaned all the grease off of it and assembled it.  It looks great.  It has never been fired, and all the serial numbers on it match.  It has "Mod.98" and "byf 1945" stamped on top of the action in front of the bolt.  It also has a small stamping of an eagle perched on a swastika on it in several places.  I was wondering how much this rifle would be worth in its present condition.  I really would like to shoot this rifle but do not want to decrease its value.  Would it lose any value if I shot it?  Also, is it even safe to shoot... I was told I should have the headspace checked first, is this true?  Finally, the cartridge it is chambered for isn't stamped anywhere on the rifle and it is unmodified so am I correct in assuming it is chambered for the 8mm Mauser?  I know I have asked quite a few questions but I would really appreciate any replies.  Thanks in advance.

Your rifle was made by Mauser in 1945.  It's chambered for the German 7.9mm rifle round, commonly known as the 8mm Mauser.

If it checks out for proper head space and there are no other problems, it should be safe to shoot.  Since late war German firearms were made by slave labor, in a great hurry, have it checked by a good gunsmith.
If it has really not been fired, it will have at least some additional collector value.

Looks like you have an original German Mauser. If it is indeed unfired the value will drop the first time you fire it. The matching serial numbers adds to it's collection value. It is chambered for 8mm.

What I find interesting is that it was disassembled. I'm certainly no expert but all the Mausers I've seen or heard about were stored assembled in heavy grease. Look for importer's markings, something in english with a town and state. Usually on the exposed barrel. If there aren't any markings it may be a war trophy which might explain why it was dissasembled. It would also add to it's value.

Mausers are fairly inexpensive, keep this one and buy a "shooter." If you are not into collecting, sell it and with the extra money buy ammo for your shooter.

For a general price check out the for sale gun boards and auctions.

www.radix.net/~bbrown/codes_rifle.html

www.gunboards.com/forums/UltraBoard.cgi?action=Headlines&BID=26&SID=1583237

OSA

if it were mine and it still had the nazi marks, i'd keep it as good of condition as possible.  buy a yugo m48a, which is basically the same gun and shoot that.