I'm thinking that the only problem with that headspace is what it does to the brass. I have had a rifle with way excess headspace and so what I did is my trick of lubing the loaded cases with case lube and loading to a moderate pressure and done. The case is able to progressively elongate rearward without stretching the web area and blowing the shoulder out to fit the chamber. This leaves a working clearance in the chamber allowing easy extraction and rechambering without sizing the cases.
Before I started doing that I was getting short case life but since doing that I haven't lost a single case to head separation. The cases fired in that chamber headspaced on the shoulder after that but even so, I continued with th lubing the cases, just very lightly, mostly with the objective of maintaining consistent case to chamber wall grip from an accuracy perspective and that rifle was accurate. In fact, all three of the Lee Enfields I do that with are pretty accurate. I also do that with my hornet that has a rough chamber which I load hot, never loses a case and shoots very accurately. Without the lube it will lose a case after two firings.