It's a late comment...but I think worth mentioning that with a very powerful springer you want to use heavy pellets and forget about the 'advertised' velocities that were done with the very lightest ones. Marketing demands that 'faster is better', but with airguns using diabolo pellets they normally don't shoot well beyond 900 fps or slightly less. If the gun is able to shoot faster....go heavier with the pellets until it's running about 875 or so and it'll be as accurate and hard hitting as possible.
Matching a heavy pellet with a powerful springer is also much, much easier on the scope. With a properly matched pellet the piston gives up nearly all of its' energy getting the pellet to move and this cushions the impact at the end of travel. Using a lightweight pellet is pretty much the same as dry firing it....the piston SLAMS the end of the cylinder with little retardation and it's this forward jerk that really puts the hurt on a scope. Also using too heavy a pellet can cause the piston to bounce back which also makes for a weird feeling shot cycle. When everything is working together the springers will shoot very nicely.
I found out all of this stuff with my first Diana 48 in .177 which is WAY too big a powerplant for that small caliber. Even with the heaviest available pellets they were screaming along and the shot cycle very harsh. Put a Maccarri spring in it that now runs Crosman Heavies at 900 and the gun shoots sweet and accurately.
After researching I bought a UTG BugBuster 3-9X-32 one inch mil dot w/green & red reticle for my 1377 multi pump. It's still holding zero after several months and still hitting pill bottles at 75 ft. I read reviews from guys using it on AK's and were very happy with it. One of it's features is the Parallax Adjustable Objective from 3 ft to infinity. I bought at rollback price at Walmart on line for $75. It's heavy but great on my 1377.
