"Many of the rifles went to India, the chambers are slightly "out-of-round" to drain water out of the bore."
"The only real problem I have ever run into is that the No.IV's that have not been FTR'd, you may twist the receiver trying to remove the barrel."
"The best thing to do is to ascertain what your problem really is. Take a sized casing or a loaded round (at the range), and load from the magazine. As you close the bolt, you must feel resistance at 2:30-3:00 on the bolt handle as you close the bolt. If you don't you need to get a new longer bolt body from Springfield Sporters, or pay $$$ for a longer bolt head. Make sure you have the seller measure the bolt head befor you by it. A marking on the bolt head means nothing these days, if he won't, run away."
If you DO feel resistance, than your chamber has been opened up and elongated by the Indian Army. There is nothing you can do short of putting a replacement barrel on your rifle. If your rifle is not FTR marked, removing the barrel can be a real problem.