Well Paddy mate, if you shorten the barrel you may well find the accuracy may suffer a wee bit, and remember of course, you will have to re-crown the barrel again - this is a finnicky job in itself but if done correctly shouldn't have much of a problem.
Thats the main point I can think of, as regards affecting the rifle in its performance, like?
Two questions for ya:
1) How long is the barrel now (without the moderator), before you take anything off, so to speak?
2) How long would the barrel be say, after you lop some off (again, without the moderator on, i mean)?
3) (ok