Not behind the recoil lug, that's asking for trouble. Behind the locking lugs, AKA, at the forward edge of the ejection port and moving back from there, it's plausible.
I think you're playing with fire though if you don't have the skills to strength-qualify the action changes you're talking about making here. I'm not going to tell you how, not because I don't think it can be done, but because if you screw it up somehow I don't feel like being held responsible in any way.
An additional consideration is that turning down the action OD (other than the issues from the interrupted cut and the strength issues that I'm not going to advise you on) is the fact that you'll be removing the roll stamped markings on the receiver which violates the GCA 68. Remember, it doesn't say "serial number" it says "markings" which is the Remington stamp, the model number, and anything else on the side INCLUDING the SN.