Your B3 likely needs cleaning more than anything. Use a degreaser, or grease cutting cleaner on the barrel, then shoot it a couple of hundred times (at least 10 shots right after degreasing. Pellets are lubed, so just shooting it will keep the barrel lubed. After 200-500 shots, you can do this procedure to clean it and increase the power a bit:
http://air_guns.tripod.com/restoring_air_gun_power.htmThat's about all you can or need to do without getting a spring compressor and taking it apart to clean and lube it. Keep your eye on the breech seal. (The little rubber gasket that seals around the breech end of the barrel.) The Chinese make seals out of yak butter, or something. You can replace that seal with a neoprene sink washer when it fails, or Archer Airguns has real ones for cheap. By the way, there's no "anti bear trap" on the B3's, so hold the cocking lever while you're reloading. It's never happened to me, but if the trigger gets pulled while it's open, the breech can bite off a finger. I've got two, a .177 and a .22. Both are really good guns for what you pay. Not really powerhouse guns, but hard hitting enough and accurate enough for general plinking or even close range smaller varmints.