Yes, provided that you hold a valid UK firearms certificate and that all the customs and excise regulations are abided by.
If you have any questions regarding these, Google 'UK Customs & Excise' and e-mal them about it.
Yes- air weapons are amongst the few firearms it remains legal for a private individual to own in the UK.
You need to tell us which rifle. Chances are that there is some legal way to own it.
Depends on where you are.
Do you mean an air Rifle? NO, Not in the United States.
Yes
no.
no if he has a permit
Laws on this vary by country.
Depends on the laws where you live.
yes
Yes. An air rifle is not considered a firearm, thus a felons possession is not limited.
Federal law says 18.