Recently bought a used Shield 2.0 PC with the 4" barrel and can't seem to find anyone selling a new recoil spring assembly. Any ideas where I might find one (other than calling S&W)?
Unless your new Shield's recoil spring assembly is defective, you shouldn't need one anytime soon. My Shield 45 has over 7,000 rounds through it, and is still on its original RSA. My 1.0 Shield 9 has about 4,000 rounds on its RSA. If your RSA wears out or breaks, S&W should send you a new one for free.
It's a used gun and I have no idea how many rounds. My standard procedure is to replace the RSA on used guns. Probably doesn't need it but... cheap insurance.