To find a bolt for a 270 model 770 engine, you can do so by looking at junkyards. It is possible that the parts may not be found online, or through manufacturers.
They did make .270 barrels for conversions of other firearms, but I'm unable to find any references to them ever manufacturing a bolt action .270.
You will have to call FN to find out.
You have a browning a-bolt rifle chambered in .270 winchester caliber.
Go to remington.com and print one off.
You need the services of a gunsmith.
AFAIK they never made a bolt action shotgun
100-1000 USD. You will have to conatct FN to find out about the history.
50-500 USD or so
IIRC, Winchester.
It will be marked on the barrel.
100-600 usd
300-400 USd