You need to buy a scope made specifically for the break barrel pellet rifles. I own two Webley guns, a Vulcan in .177 and a Patriot in .22. Accurate and deadly out to 45-50 yards. 400+ barn pigeons would disagree on the inaccuracy of an air rifle scope on a break barrel gun.

Try http://www.pyramydair.com/ . You will also want a good scope mount, one piece, not a two piece. Your rifle likely has a groove perpendicluar to the barrel in it for a scope stop along the top rail. This keeps the scope base from moving position along the rail, as the recoil impulse is pretty jarring compared to other air rifles like pump and PCP.

I use a Beeman 4x scope, and it has worked well for over 15 years.