At such short range anything should be ok. My kjw MK1 gets a tighter grouping than 1" at 35 or so feet,(if you can pull the heavy trigger steadily, many can't) My G&G xtreme45 not quite as accurate but easily matches your revolver's grouping but at 35'. Both are inexpensive guns. As far as bb pistols go, I've got an Umarex walther cp88 that'll put a pellet in a rabbits head at 75' easily.(Had to take a couple out as there was a rabies scare and I have dogs). It wasn't expensive either.
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