Resting the forend on a bench is no good mate, I do a lot of pellet testing and have trialled many different holds and rests, the best I have come up with is the following-
Put a shooting bean bag on the bench and karate chop it to create a channel, rest your arm in this channel and make a thumbs up, rest the rifle on top of your fist with the thumb locating the rifle laterally, a shooting glove also helps.
Now your right elbow is going to be floating unless you have a well designed L shaped bench, in which case you can support your right elbow (assuming your a RH shooter of course) otherwise you will have to tuck your elbow in to prevent any wobble, make sure the rifle is not touching anywhere on the bench and concentrate on consistency of your hold and follow through, to facilitate this freeze in place after the shot and check to see where the crosshairs end up after each shot, if your hold is consistent the crosshair will end up in the same place each time.
This is the only reliable method I have found to shoot a springer off the bench, basically you are isolating the rifle from the bench and putting it in a position where the recoil is absorbed by yourself in a more natural manner.