Been studying this idea lately. Reading about Savage-type barrel nut conversion, etc. Not sure what I believe or what I understand at this point. On a Rem, some are saying that you must fasten the recoil lug to the receiver somehow, by welding, or pinning. I don't understand the need for this, so, my question is: Why ? Let's say you want to re-barrel. Unscrew the original and then begin the process to set up the new one, thread - chamber - headspace, etc. Finally the new one goes on and stays (for a while). You just switched barrels. Hmm, I think I want to try something with the old barrel; unscrew the new one and screw the old one back on, but this time no setup machining is required, sure goes quicker. You just switched barrels. Repeat as desired, or even add a third barrel into the rotation. ---------- So far, it's not been necessary to have the recoil lug pinned in any of these operations. Each particular setup is a complete and distinct rifle in it's own right, it doesn't know any "switching" ever happened. What am I missing ?