They shoot great out of my Crosman 1377 .177 pump pistol out to 20 yards or so, but I won't use them in any of my rifles for fear of causing damage to the rifle. I've read reports of people who used them in their rifles and the they say accuracy drops off dramatically as the distance increases, something I can attest to with regard to my 1377 pistol. As for the concern over damaging the gun,,,,,, the theory is that the pellets are so light that they don't provide enough resistance for when the gun is fired causing "piston slam". I am certainly no air gun expert so I'm not saying the theory is correct, but I've read enough people, much more knowledgeable than me, make posts advising not to use them in springers so I never have.
Jeff