I will say it again, Remington barrels will often interchange with a slight decrease in headspace, but you have to know how to check it or take it to a gunsmith and have them check it. Savage and Rem 783 barrels headspace with a barrel nut.
This is not the kind of thing that a novice should be doing without hands on help, in the very least.
I have never seen a Ruger, Winchester, or Sako barrel exchange without major issues.
