I don't know if you are new to springers, but they do not like to be benchrested in the same way you would a powder burner or even a compressed air/gas air rifle. You may prop your left hand (assuming you are right handed) up on a bag but the rifle should rest on your open palm. Also, make sure your contact points are very consistent. Moving your left hand slightly up or down the forend from shot to shot will result in poor groups. Use a light to very light hold.
At 25 yards a 34 should be able to do even better than 1/2" groups.
Either CPLs, FTS, Trophy, JSB Exact Express, or JSB Exacts, are what most of my springers like. Don't give up until you have tried most of them. If none of them group around 1/2" at 25 yards, you may have another issue. At that point I would make sure you aren't suffering from parallax error, or a screwed up crown, breech seal, or main seal.
Good luck and let us know how it turns out.