My used barrel fit really good when I first got it, but it did have that lateral motion ever so slight, but it was there.
I cleaned the lug area where the pin fits and rotates, and applied a slight amount of J B weld to the lug radius.
It doesn't take much, and I used pam to spray the pin, and inside around the pin on the receiver so as not to JB weld my rifle together, and closed the action, letting it sit overnight.
Next morning opened the rifle, took the forearm off, cleaned and greased the pin, and it's tight as a drum with no movement at all.
Looking at the lug after taking it apart I noticed the pin made full contact on one side with the lug, but the left side filled in nicely with the JB weld whch shimmed up the space, thus eliminating the play!