Mags wrote:.
I have a theory about that. The outer mag tube is a piece of steel curled to form a tube. The tube seam is not welded. The edges just tough each other. You can see this 'open' seam on the back of the mag tube by looking through the loading port on the tube. I suspect the 'open' seam allows the outer mag tube to shrink more so from the extreme cold and to clamp/grip down on the brass inner tube.
If you still have the 'vortex' temps, try TNman's suggestion with the synthetic oil and put your Henry back out overnight in your truck. Next morning, see if the inner tube is removable. I'm curious to read about what you find out.
Greyhawk wrote:... I could not budge the brass tube to extend it and load the magazine, it would not even turn. I have never had this happen under normal conditions, and it worked just fine after the rifle warmed up...
I Think that you are probably on to something.. It did seem more 'clamped' rather than there being some moisture 'frozen' in it.. Also, my rifle came out of a humidity controlled gun safe right into the back of my pickup, so the likelihood of it being a moisture issue is just about zero. So.... My Henry 45 colt and 45/70 have been BANISHED to the woodshed! Each morning over the next week I will check the temperature and try the magazines and see if they operate normally, seem sticky, or are just plain 'clamped.' I'll let you know the results!