The only real other situation that I can imagine is usually that it may be a normal Model 70 barrel and motion using a substitution XTR inventory. That is unlikely although...I believe that it is as you explain, an unmarked XTR. This extractor has drawn lots of flack over time, https://winchester70featherweight19898.bloggerchest.com/26640685/a-secret-weapon-for-winchester-model-70-featherweight-30-06-review