5-1500 usd
1984
for a rifle it is thought to be a .50 calibre but a gun company made there own for there own sniper rifle the .408 calibre
Need a detailed description of all markings.
$75-$150, depending on condition.
100-1000 USD or so depending on EXACTLY what you have and its condition.
arund 450,000 or so, depending on calibre
The .243. It's basically a necked down .308 Winchester.
Any other markings? Is it a bolt action?
No
The largest calibre i came across was 30 calibre russian rifle (gas chambers punctured to make it bolt action). owned by a retired army personnel. I guess they allow them to purchase it from the ordnance. Don't know if they can sell it though.
Have you tried their web site?
This all depends on the calibre of said rifle make and model :)