What is the most powerfull air rifle?

Answer 1

I believe it is the Air Force Condor. 1250fps (with the right ammo)

No firearms certificate is needed in the USA, but you may need one in other countries. The reason the Condor is so powerful is because it uses a Scuba tank to charge it to 3000 psi. The Condor is in a class of air rifles called PCP ( PreCharged Pneumatic) they come in several calibers including 9mm, 45 Cal and 50 Cal. They are capable of taking down a deer or boar.

Do you need a firearms certificate for the condor.

Not in the United states you don't, ( with the exception of a few locations like New York and a few other cities.) but you may need one in other countries