What's funny is I asked the bolt changeability question not even a month and a half ago in a thread titled"need help identifying the stock on my carbine"in this very forum. I asked if I had to be concerned with the headspace if I were to change an Underwood round bolt marked .u. with another New Old Stock still in the wrap Underwood round bolt marked the same. I was told that it would be fine to do so, just like I have read on many other forums that it is okay to do so safely. No rebuttal at all from any other forum members whatsoever. Now that I (a new forum member) pass along the exact same information, the beginnings of a forum thread meltdown.i guess it boils down to who is giving the advice, a new member or a long time member of what kind of reaction will come forth. And as for the forum member that warned the OP of taking advice from someone who knows less then the Op, I'm not really sure how he knows what I do or don't know, but we will stick with that because it sounds nice