User blog comment:Xanneer/PHYSICS!/@comment-24911350-20140529232559/@comment-24911350-20140530055715

The recoil on CR is primarily used to change its own direction quickly, it's never had much effect on Ruby aside from when she loaded the gravity rounds. Every time she's fired it in its gun form, she's also been aiming quite a bit upwards which would lessen the backwards effect of the recoil. The gun form may very well even use a separate magazine or type of ammunition, because the one that we've seen is only accessible when CR is in scythe form, that's just speculation though, although it is heavily supported by the fact that CR is both magazine-fed and fed with individual rounds, as well as being both bolt-action and semi-automatic in its separate forms.

Yang also wasn't firing her typical shells at the Nevermore, they were the rocket-like ones she also used in the fight with Melanie and Miltia. Yang also punched Junior across the club and through a glass plane without using her shotguns, so you can't really say they're responsible for most of the knockback her punches have.