You have a rifle which fires an 8mm cartridge, and there's a number 599 on it somewhere which may or may not be a serial number. That is all that can be derived from your question - what which 8mm cartridge it fires, not who the manufacturer is, not what model of rifle it is - the things one would need to know in order to assess the value of your rifle. So, there is no way to give an answer based on the extremely sparse information you've provided.
What couldn't you kill with a rifle of any kind? Of course you can kill a hog with an 8mm.
Depends heavily on the condition and originality of the rifle. Anywhere from $150-$500.
A 1915 Erfurt 8mm rifle is worth between $200 and $2,000 depending on its condition. The actual value varies based on individual sellers and the history of the rifle.
$450
8mm Lebel
@ 2000 FPS
Your guess is as good as anyone's here. There were several types of rifles made for the 7.82x57 (aka, 8mm Mauser) cartridge, these rifles were manufactured by several different arsenals, and the serial number does nothing to indicate the purpose. Yours might not even be a military rifle - your question gives us no indication of the manufacturer or model - for all we know.
That would PROBABLY be the first rifle to use a smokeless powder cartridge- the French 8mm Lebel.
No. If you try that the gun will blow up and you might be injured. You need 8mm Mauser ammunition.
Blue Book of Gun Values
Mausers of the world by rober w ball